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Show HN: OffChess – Offline chess puzzles app
Hi HN!

I'm the developer of rdx, a mildly popular ad-free, privacy and user friendly Reddit client. This time, I made something for a very specific use case: solving chess puzzles with no internet.

Why? Well, my Wi-Fi is terrible in the bathroom—and that's where I do some of my best thinking. I tried printing out “mate in X” puzzles to solve offline, but they weren’t fun without interaction. So I built OffChess.

OffChess is an iPhone/Android app that contains over 100,000 chess puzzles, fully offline and completely ad-free. You can solve puzzles by category (Mate in 1/2/3/4/5, tactics like pins/forks/skewers, or openings like Sicilian/French, etc). You gain or lose points based on how you perform, so there's a light rating system to keep things engaging.

No accounts, no tracking, no monthly subscriptions, no internet required. Just pure, old-school tactical chess training, wherever you are.

You can check out the iPhone/iPad app at https://apps.apple.com/us/app/chess-puzzles-offchess/id67447... or the Android app at https://play.google.com/store/apps/details?id=com.offchess

Would love feedback, bug reports, or suggestions.

Thanks!

Nice project!

As it was not clear from the description, there's a one-time payment (4.29€) to get more than 7 puzzles in a day.

Lichess also offers a good alternative to this, although their offline support is limited.

> offline support is limited.

You are limited to 50 puzzles when off the network, and when you reconnect, the next 50 (or the delta between how many you played and 50) are redownloaded.

TacticMaster on F Droid seems to have all the same features for free.
A great app no doubt but the descriptive hints on OffChess and a different rating system set OffChess apart from TacticMaster.
CT-ART 4.0 is the gold standard. Again, not fully free, but it has some very instructional features, like playing against alternate moves, solving mini versions of a puzzle, playing the opposite side etc. Used it for years.
To be fair you shouldn't be sitting in the bathroom for that long because you'll develop hemorrhoids.
  • eru
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Just use a standing potty?
I thought squatting was all the rage.
To be fair you shouldn't be sitting in the bathroom for that long because you'll develop hemorrhoids.

Maybe he's really good at chess?

(Unlike my former co-worker who would monopolize the one men's room stall for two hours at a stretch doing chess puzzles on his phone, and I'd have to go to the IT building. Gross.)

Amazing! Would love “premoves” so that I can input the next move before the first move’s animation completes. This will help maintain flow state for your more experienced users.

See chessbook for an app that does this really well.

I will look into the app you suggested and try to implement premoves.
Great! ...but doesn't work on my google-free Android. Ie, it requires play services. Please fix this :)
Will have to implement a different billing system for that so it will take some time.
great app, I like the adaptive style, but one piece of feedback is that, sometimes it is not clear what the goal is. For example, the language "Brilliant queen win ahead!" tells me, right, I am going to checkmate for the win with the queen in this game. But, actually the puzzle is to instead win the queen piece. "win" in chess to me always means checkmate.

Overall great app.

I will change the confusing wording like this but for now I can tell you this, if it mentions a piece by name then the puzzle is about winning that piece and not the game. Thank you for trying the app out.
Wait, are you saying that you have puzzles where the "winning" moves aren't the best moves? If so, that is not good.
Subtext is that the solution is always the best possible move sequence. OP’s comment is clarifying that sometimes after executing the best move sequence, the puzzle ends with a capture, and sometimes ends with a checkmate (“winning”).
No, the winning moves are always the best moves.
The goal is always the best move. You shouldn't think of "what is my goal?", you should be finding the best move. This is something I struggled with as a beginner. There is always a best move, find it. Don't search for "the goal".
Awesome. I’ve never understood why Lichess limits the offline download to 50 puzzles.
For what it's worth, the entire Lichess corpus of puzzles (over five million positions with solutions and theming tags) is available for download in CSV format at https://database.lichess.org/#puzzles
I downloaded this and wrote a small program to filter on 1, 2, 3, 4, and 5 move puzzles. I also segregated by rating. Then I ran them thru stockfish (there are some errors) and generated several years worth of daily puzzles. It’s part of a daily chess feed I have for my club. So, puzzles get harder thru the week, similar to NY times crossword puzzles. I uploaded this to my cheapo web server. I give credit to lichess and provide a link to play the position on the lichess.org website.
It’s not worth much when I want to use the Lichess app on an eight hour plane ride to solve them :)

I like the feature because it updates my rank when I get internet restored. I just wish they cached more than 50 offline.

Great start! Gentle feedback:

- Text hints should probably be off by default, they give too much of a hint.

- Auto-advance to next puzzle would be helpful, clicking “next puzzle” gets tiresome.

- Typo in the puzzle categories list: “Egnlish Opening”

1. I enabled them by default because I thought most people won't even know about their existence if they weren't there but if someone is bothered by them they will definitely find the menu item and disable it.

2. I will add an option to enable auto advance in future update.

3. That typo is embarrassing — thanks for catching it! There’s always something that slips through.

Nice app (bought the in app purchase).

I went to find the setting (independently of this message, I'd prefer it off by default, but seems fine either way) and I actually can't open the menu, which I assume is the three dots I can see in the top of my phone. It appears to be behind my notification bar?

The Offchess text in the top left is behind my phone's clock as well. Maybe just some padding is needed?

Android 15, Nothing phone 2 if it matters. Message me if you'd like more details.

This happened because latest Android version explicitly needs to be told not to go edge-to-edge. It's been fixed, stalling in the Google Play App Review, might take a day or two but as soon as you update it will be fiex. Also, yes there is a menu item to turn hints off.
Nvm, probably the same as this I assume: https://news.ycombinator.com/item?id=44500344
Fixed now, you can update from the store if you don't have auto updates on.
Can confirm the fix works. Thanks!
Can you tell us about the tech stack you used and why?
I don't want to detract in the slightest from this fantastic app (I will be getting it shortly), I just want to point out another set of Chess puzzles for folk like me that enjoy this stuff. Check out the World Champs app, it has puzzles (mostly) taken from actual end games:

https://apps.apple.com/us/app/chess-puzzles-world-champions/...

I recently deleted the chess.com app due to monthly price, so I'm thrilled to start using this app instead! Good job!
Thanks for your review.
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Could the hint not show the full move?

i.e. just show the piece, not the piece and where to put it?

Very nice! but why not a webapp as well (for those of us who seldom use their phone and can get bored at the office)?
OffChess website will be soon available in beta with multiple features.
Probably because lichess.org exists?
Solo developer, no ads, no subscription. Take my money! And thanks for writing decent software.
Thank you for your kind words.
I'm just about to leave for a long international flight, so this is absolutely perfect for me!

Glad I saw the comment about it being paid so I could get to the purchase screen before I lost internet. (As a side note, it says "Buy now for $3.99" but it's really $5.99 in my currency. Not sure if you can make the button match to the price in the locale)

It is just a placeholder for the price in your currency. Sometimes the play billing library takes a little while to get the price from the server. If you swipe up the app from app drawer(force close) and open it again it should show the correct price in your currency.
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This looks really cool! I can't remember what article I was reading the other day but it was advocating for local first software as being the true goal of creating user friendly software -> this app absolutely meet's that goal. Looking forwards to using it.
The article from the other day for context: https://news.ycombinator.com/item?id=44473135
Great read, thanks for sharing.
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Very cool app. Chess.com costs too much and lichess is rather ugly and has barebones puzzle support. I like how you can choose different categories. Will be using this from now on. Btw you have "Egnlish Opening" misspelled.
For tactics I really like chesstempo.com. It has free, unlimited puzzles. It is to my mind superior for tactics training. It also has a comments feature which I really like.
Try lichess' beta app, it's much more user friendly, even if it's missing a couple of features.
Thanks for your generous reply and Oh my god how did I miss that, will fix in the next update.
  • tdiff
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I wonder where were those 100k puzzles sourced from?
TacticsMaster on F-Droid also says it has 100k puzzles, sourced from https://database.lichess.org/#puzzles, though that says it has 5 million puzzles, so perhaps 100k is just a coincidence, a nice number, or maybe of the 5m there's a nice subset.

> Generating these chess puzzles took more than 100 years of CPU time.

The page includes a link to the puzzle generator and tagger for interests sake.

To add to this thread, here's how Lichess generates chess puzzles - https://github.com/ornicar/lichess-puzzler
Not OP but generating puzzles isn’t hard if you have a database of games and I’ve done it myself.

For each game just fast forward to the end and ask for Stockfish to provide the solution. If it’s guaranteed “mate in X” then you’ve got yourself a puzzle. You can have a classifier that grabs other puzzle types too (“win the queen in X” for example)

At scale, It gets a little harder trying to explain the solution. There is often a combinatorial explosion of move possibilities, so it’s not easy to just say MATE IN 4 if there are 40 or 50 potential responses all leading to mate. Granted they are obvious mates but there may be users who do not see the obvious mates.
If you would like a chess puzzle book, try Raymond Smullyan's The Chess Mysteries of the Arabian Knights.

https://raymondsmullyan.com/books/the-chess-mysteries-of-the...

Love the app! Would love it twice as much if you allowed me to turn off the sounds (it turns off any existing podcasts or music).
Thanks for the review, will add a toggle in the next update.
  • AiAi
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Thanks for rdx, it’s the way I use reddit nowadays.

I have only used OffChess briefly but one feature request I have is to remove the possible path of the piece when clicking on it (like Lichess).

Another improvement would be the placement of the “next puzzle” button, that seems to be in a crowded place.

Updates are coming to rdx as well and thanks for your feedback on OffChess, will look into your suggestions definitely.
Are you going to make a desktop client?
This should work on Macs by default, will look into making one for Windows/linux.
Nice! Quick feedback:

- it plays sound even when my (iOS) device is muted

- would love an option to automatically go to next puzzle

Thanks for your feedback, In the upcoming update I will... 1. add a toggle to disable sounds. 2. add an option to enable auto advance in future update.
It plays sound when the device is muted, has no preference to disable sound for the app, and moreover, the sound effects interfere with playing media, i.e. when I make a move the app pauses my music, playing in the background, to make a sound of a moving pawn.
Thanks for the feedback, will be fixed soon.
I would love to see something like this for GNU / Linux desktop. Great work!
There is a nice native app for offline lichess puzzles. Written in rust:

https://github.com/brianch/offline-chess-puzzles/

One day, I hope.
Nice app. Using moto edge 60 pro. The app navigation gets hidden under the phone navigation icons. I'd like to pay. Except without user login, I am unable to figure out if the purchase can be linkedin to my 2-3 devices (each of which may use a different Google account)
Thanks! A couple of other people in this thread have mentioned that bug too and I'll get it fixed ASAP.

There's no login required since the app uses Google Play Billing on Android and App Store billing on iOS. That also means purchases are tied to the Google account used to buy the app, so unfortunately they can't be shared across different accounts.

I hate the annoyance of apps forcing you to create an account before you even try them and that's exactly why I kept it simple and login-free. But yeah, the trade-off is stuff like what you pointed out. To balance that, I made it a one-time low-cost purchase instead of a subscription. Hope that makes it fair.

> That also means purchases are tied to the Google account used to buy the app, so unfortunately they can't be shared across different accounts.

I don't have hand-to-hand experience with Google Play, but quite a few of those billing platforms offer "discount codes." So to help the GP commenter, I would imagine they could email you from their purchasing Google account and ask for 100% off codes for their other Google account addresses

I don't know how to help the sibling comment, short of you just straight-up making them a custom .apk without Play Billing. FWIW, it's actually absolutely painless to host your own f-droid repository <https://gitlab.com/fdroid/fdroidserver#what-is-f-droid-serve...>. It's marked AGPL but despite its name one doesn't need to run that package to host a repo, just $($HOMEBREW_PREFIX/bin/fdroid update --verbose --create-metadata -W error) and then $(rsync -Pav --delete ./repo/ your-awesome-host:/repo/)

It's so painless you could even do that per user, as in lucb1e-fdroid.example.com or lucb1e-a6d7c104-e9b1-4ddc-ad5a-470e51bb5069.example.com

> There's no login required since the app uses Google Play Billing

...so it requires logging in with a Google account. That means I won't be able to buy the app on my phone

A one-time purchase for an offline privacy-friendly app is 100% fair and the price point and free tier seem great to me (someone upthread said it's like 4.7€ if you want more than 7 puzzles per day iirc), but please just add an option to send you money directly via e.g. IBAN. It's one of the few privacy-friendly options and you also get to keep all of the money

Most other options cut people out: paypal doesn't work half the time ("sorry, something went wrong" when the algorithm hates you today), stripe has issues when your bank and residence country don't match, credit card requires a good credit score, etc. It's all data- and algorithm-based, whereas banks are legally obliged to give you a functional account because it underpins so much of society nowadays. I'd be happy to pay for the app even without using it as a way to add my 'two cents' and hopefully make this more worth your time

I will definitely look into supporting alternative payment methods, someone else also has a de-googled phone and asked for the same in this thread too. I wonder if any of the alternative payment methods has a sdk that I can integrate directly or I will have to go the old school way of using software keys.
A Google account is free and only takes a few seconds to make.
Huh? Try it, since like ten years it requires validating the account with a phone number, which in many countries requires going through government verification. That alone takes a while to set up if you want a new account that isn't linked to other things already. It's not a quick as generating a new password in your password manager and coming up with a non-taken username anymore

You also can't log into this app specifically, it will tie all apps on your device to this one account. Nobody should be doing this, it's like logging into the Chrome browser and tying all pages that have any sort of google service on it (embedded map, youtube, analytics, ads) to the phone number and thus identity you signed up with

> one of the few privacy-friendly options

almost certainly implies it's not a technical hurdle that they're facing. Plus, purchasing would require giving Google payment details, which would necessarily include billing address, and now it's tied to your phone. I could very easily imagine that giving a lot of folks a lot of heartburn

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I have an iPhone 16 Pro and there is an annoying delay between tapping a move and the piece moving
Is it the animation of the piece moving? I’ve tested it on a bunch of iOS devices and haven’t noticed anything odd, but I’d love to take a closer look. If you can, please share a video or GIF. It’ll really help. You can email it to me at support@offchess.com. Thanks for trying my app out and giving feedback.
  • shric
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Somehow today (I reached the limit yesterday) the delay has gone away, so I can’t reproduce it.

What happened, from memory:

1. Tap piece at original location

2. Tap piece at destination

3. Piece animation commences

4. Piece animation finishes

5. Move sound occurs

Everything was smooth except there was an approximately half second delay (may have been less) between 2 and 3.

Cool app. I’ve been thinking of building a similar PWA for a while now, might actually do that.
Even I thought of first making it a PWA too, the only problem is storage of the puzzles database.
  • B56b
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Oh is there a reason you couldn't use IndexedDB to store the puzzles?
Love it! The notification bar on my OnePlus 13 blocks access to the triple dot settings button on the top of my screen. ither than that it's clean.
That's been fixed and the update - as soon as it is approved by Google should be available on play store.
Very cool looking! Downloaded. What tech did you build it with? :)
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Swift, Java, Javascript, Sqlite etc.
This is cool! Is there a chess board library that you used or did you have to built it from scratch?
I built the board from scratch but used the awesome chess.js library by Jeff Hlywa for move validation.
Where did you get the puzzles from?
  • McDev
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If it were my Chess app, I'd get them from the Lichess open database (currently at 5M puzzles): https://database.lichess.org/#puzzles
So did I.
Congrats on the launch!

I was wondering -- how does the point-based rating system work?

It takes both yours and puzzle's rating in consideration while calculating. Just below the chessboard you can see "+12 -10" that means this puzzle will gain you 12 points if you solve this or you will lose 10 points if you fail.

The system is based on ELO with the main difference being that the K factor in OffChess is variable, https://en.wikipedia.org/wiki/Elo_rating_system

  • wery
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I can't select the settings button on my Pixel 8 :|
I am so sorry about your experience, will be fixed by tomorrow if Google approves the update soon.
You attribute chess.js as MIT license ... But I'm curious where you sourced 1,000 addon puzzles for $3.99.

.... As I doubt you thought them all up yourself. You may want to attribute your non-derivative assets.

Thank you and God bless you my friend :)
Nice. Any retrograde chess puzzles with this?
Not yet but interesting idea, I might add these as a category in the future.
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Nice, bought to replace 'chess tactics puzzles' the addition of rating changes sold me.

Too late did I notice that there is no share fen button. I use that for harder puzzles when I want to understand why a given solution wouldn't work. Mostly just share to Chessis.

Share fen and share pgn buttons will be added in the next update.
For some reason I cannot download it on Android with Aurora Market, perhaps it is too new?
Only available on play store for now :(
Very cool!
I have TacticMaster (available on F-droid) but your app looks more polished and will have to give it a try as well.
Nice app and props to you for open sourcing it, thanks for your good words about OffChess.
Not my app, just a user, credit goes to this person https://github.com/jazzm0
Neat, just downloaded it off of fdroid. Really cool, thank you!
This is a nice app, but I have one bug report: When I tap on a piece, and it can capture another piece, it looks like it just can't move that way. Capturable pieces should have their background change somehow, to indicate that I can capture them.
Yeah, that’s more me being lazy than an actual bug. I left it like that assuming most people would figure it out anyway — but you’re right, it’s bad design. I’ll add a border around the "capturable" pieces.
Thanks, it left me a bit baffled the first time, as it seemed to say I can't capture the piece, when I knew I could. I tried anyway, and it worked, but it was confusing.
That’s more of a feature request not a bug report
[flagged]
The app is full screen on my Samsung mobile so your bottom navigation is underneath the onscreen Android navigation and unusable. Happy to submit an issue and screenshots if you have a GitHub repo.

Other than that, it is working nicely so far.

I'm really sorry about your experience. Could you please let me know your device name and screen size? I will make sure to fix this, along with any other bugs people report here and push an update to the app stores by tonight.
Update: I have fixed the issue, the update will be available as soon as Google approves it.
Same here, there's some text at the top that's below my clock and icons:

https://imgz.org/ibGDKfuf/

That's not supposed to happen, there should be space left for a status bar and a navigation bar. Can you share the make and model of your device?
Reporting same bug, on Google Pixel 8.
Yes, it's a Nothing 2.
Fixed, update should be available as soon as Google approves.
Thank you!
Did you update? Should be fixed now.
There's no update for me yet :(
Sometimes it takes a while for Google Pla to distribute the update in different parts of the world. Check Google Play in a few hours and it should be there. I have confirmed with multiple people and they say the issue has been fixed with the update. If you still have the issue you can always mail me.
I got the update and the issue is fixed, thanks! Still no border when capturing, though (I don't know if that's been implemented yet).
> Still no border when capturing

For that you will have to wait for the next minor update.

You had me when you said some of your best thinking happens in the bathroom.

Looks cool. On Android the UI seems to extend below the status bar at the top and below the drawer at the bottom of the screen which creates some overlapping though.

I have fixed the issue, just waiting for Google to approve the app.
[stub for offtopicness]
Note that the discussion continues in the collapsed comment by tomhow: https://news.ycombinator.com/item?id=44499848

It says "stub for offtopicness" but, skimming them, literally all comments are on-topic. Not all substantial ('very nice app', 'whats the tech stack?') but a lot of other comments are a normal amount of substantial and also in there... I don't get it, but note that you can expand that subthread

Sorry about this. I've moved most of the comments in the stub back to the main thread.

We've recently had some threads about new product announcements in which the thread quickly fills up with "booster" comments from new accounts or old/dormant accounts that come back to life just to post these comments. The "stub" is a way to hide those comments without penalizing/hiding the main thread and the product it's about.

We were getting some emails and comments suggesting that this was happening here too, so I started trying to address it by moving some comments into the stub, intending to spend more time figuring out which ones were authentic and which ones seemed inorganic, but was slow to get back to it.

I think in this case, most or even all of the comments are actually organic or authentic; people just really love a good chess app!

Sorry for the confusion!

Thank you for clarifying! No worries about the delay of course, we all have more things to do. Do I understand correctly that a 'booster comment' is about steering the conversation / making the product look well-liked to those who open the thread, and not that it boosts the submission up in some way? (If you can say that in light of people gaming it)
In this case the "things to do" was sleep, and the overarching issue is trying to do moderation work that really requires peak cognition when it's late and you're falling asleep, then leaving it half-done.

By "booster" comments we just mean comments that are highly positive but low on substance. "Great app!". "Congrats on the launch!". Comments like that are often an indication that a friendship network has been rallied to show public support and create "social proof". But often these kinds of commenters try to get clever and add in Dorothy Dixer questions about the tech stack or something else to make the comment seem more authentic and substantive, and enable more details to be shared.

Often when that happens, it's green (new) accounts or old/dormant accounts posting the comments and upvoting the thread, but there wasn't much of that here (though there was a little, which is what aroused suspicion).

But these comments don't have any effect on the thread's ranking. It's only a vibes effect.

I can assure you I didn't ask a single person I know to comment on this, most of my irl friends don't even know what hackernews is. All comments, even the ones that are hidden now are organic. Even I thought it's weird that an 8 year old dormant account decided to comment on my post but I have nothing to do with that.
I believe you (and didn't actually think you'd rallied anyone, we thought something else was going on). Sorry for the bother!
If my comment was marked in this sweep, does that mean my account is marked as suspicious/booster?
No not at all, nothing was "marked", just moved temporarily then moved back. Sorry to cause alarm :)
I posted this

``` Hi ,Congrats on the launch. I built a free iOS app also which has chess puzzles.

https://apps.apple.com/us/app/knighty-chess-puzzles/id674524...

Would appreciate feedback. ```

Not sure if that's why it was moved to `stub for off topicness`. I wonder if it is some kind of categorisation logic based on text.

I'm also wondering if it's an automatic classification. Wouldn't expect that on HN, but the posts in there are so random that it almost must be.

As for that specific comment, to be fair, I could actually understand: promoting your own product in someone else's thread without really saying anything at all about the submission (topic) that was posted could be seen as off-topic. I don't really mind it (I don't think I voted on it), but I could see a human also classify it that way

Yeah , that's fair. More than promotion i was trying to suggest i had also built something similar and kind of understand the product space. It's this dev thing, can't shake it off i guess. But i get what you meant.

Apart from that i have a theory that there is a lot of ML based ranking and classification that is happening at the backend.

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Why would you in 2025 only build for iOS?
This was a swift app. I wanted a bit more native feel and didn't go for react native.
Can you please explain what it means? I have been using HN for years and only seeing this for the first time. Seems like some mod action but searching on google didn't return anything.
https://news.ycombinator.com/item?id=44504071
I’ve seen dang do something similar before to clean up a thread of off topic comments.
Yes, very strange and I was wondering why my comment which is on topic was added here…

There are other comments which are clearly on-topic, e.g. direct feedback about the app, which have been relegated to this weird sub-thread.

If this is a new feature, I’m not a fan of it. We have downvotes for off-topicness.

In my experience, nothing beats the puzzle quality of ChessTempo. Curious how this compares to that.
Hi ,Congrats on the launch.

I built a free iOS app also which has chess puzzles.

https://apps.apple.com/us/app/knighty-chess-puzzles/id674524...

Would appreciate feedback.

Nice app, I dig the logo.
Thanks man. I would also suggest creating a leaderboard with XP for gamification
Hey , i would also suggest posting in r/chess
Thanks man, I will definitely do that.
This alternative: https://github.com/brianch/offline-chess-puzzles is linked from lichess puzzle page.
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A bit off topic, but since you mentioned doing your best thinking in the bathroom, two things you should try are (a) no caffeine, and (b) no soy. These should dramatically cut down on the number of times you have to go and how long it takes.
I love my time there but thanks for your suggestion.