Launch HN: ASim (YC S21) – Mobile app that generates mobile apps

Hey HN, we’re Daniel and Daniel (the Daniels) from aSim (https://asim.sh/). aSim is a mobile app that can generate immediately usable and shareable mobile apps from your phone.

Tools like bolt.new and v0 have made it easier to build websites by just chatting with an LLM, but things have been lagging on the mobile side. We’ve always been suckers for well-made mobile apps, but today, it is still extremely difficult to build mobile apps with LLMs on your computer, and nearly impossible to do it from your phone.

We built aSim to make it easy to build prototypes, “trinket” apps, or just random fun things all async from your phone. You can check our landing page (https://asim.sh/) for some ideas of different types of apps. Hopefully we can bring some life to your side project graveyard, or at least make the graveyard even more numerous.

Here’s a demo video of the generation process: https://youtu.be/_3VCl13oMGc

And here are the actual one-shotted apps I made in that video:

- https://asim.sh/@dli/s/157003/make-an-app-where-i-can-upload...

- https://asim.sh/@dli/s/157014/make-me-an-app-that-is-a-clone...

- https://asim.sh/@dli/s/157006/make-me-a-chess-timer-app-for-...

All of our app generations also get access to a set of APIs that help get the ball rolling on some basic functionality. These APIs range from LLM usage and image generation to having shared state with your friends, and globally among all users. We’re always on the lookout for new API integrations (i.e. Spotify and Maps) so please let us know if you need any!

We’ve had a small cohort of beta users that have been making what we think are some pretty cool apps. Here’s some of our favorites:

- Pokemon-style Gacha Game - https://asim.sh/@evan/s/126948/elves-vs-monsters

- OpenStreetMap stats: https://asim.sh/@lake/s/104102/osm-stats

- Star wars idle game: https://asim.sh/@jojaspero/s/29102

- Find your Meyers Briggs - https://asim.sh/@typewhisperer/s/135964/jung-mirror (<-- just for fun, you don’t have to believe in MB :))

- AI Tic Tac Toe - https://asim.sh/@hashmelons/s/105561/ai-tic-tac

Behind the scenes, we’re generating a modified version of Typescript React Native that can be parsed and compiled into simpler instructions that can be sent to mobile devices on the fly. We’ve ripped out some parts of the TSC library, as well as lean heavily on AcornJS to massage the (mostly usable) LLM code into something that can actually be run. We have a bunch of static analyzers, as well as leaning on web runtimes to catch runtime errors (as well as take screenshots), though at the very end of the day, we lean the most on our users to play around with their creations and remix them into something great.

It’s currently completely free to use, so we hope you check out aSim at https://asim.sh/ and enjoy it as much as we have while building it! Let us know what features you’d like to see and any problems you have with your generations.

love it. but that makes me think that development is no longer the bottleneck —distribution and positioning are. and my bet that the ASim fucntionality will find it place in the current media platfrom.

say, if tiktok launches an ai app store, it won’t be for complex software—it’ll start with low-friction, high-retention apps: ai-powered video enhancements (think face-swaps, lip sync, object replacement) or micro-utilities, something like ASim does.

for platforms, it’s obvious—more engagement, higher monetization, and a new vertical.

for creators, it’s a no-brainer—why funnel traffic to some app store when you can keep users inside tiktok, get them to install, and even monetize directly?

even the infamous 30% app store cut could be creatively sidestepped—imagine launching your own meme coin for in-app purchases instead.

thanks for the kind words! yep, this is exactly how we're thinking about this space as well! we think as software dev costs compress, it'll become a new modality of expression, similar to how we've seen images and video platforms take off as creation costs start to really compress.

cool! happy to connect with you folks! my twitter: kidrulit

This reply would be a lot easier to read with some capitalization after punctuation.

There at least 2 capital letters in that post.

The embedded mini-app ecosystem is a real model in China. Wechat being the most popular platform. Douyin also has a good share of it. You even see such ecosystem in payment apps like Alipay. I'm also certain there are special deals with Apple structured around this concept.

ya - i think the replication of the wechat super-app has been attempted so many times in the west at this point, but maybe agi coding solves this...?

the playbook works relatively well outside west hemisphere. grab, gojek, gozem, yassir scaled well beyond services to fintech.

Development hasn’t been the bottleneck for a long time people are just lazy

It’s only the bottleneck for orgs that don’t know how to keep focus and bloated orgs with too many teams/managers/engineers.

And scrappy startups made by businesses school dropouts (and grads)

[Answered]

Does it play sound at this stage? or other media (eg video, beyond still images and text and UI?)

EDIT Thank you for making and sharing this -- it is pushing the future closer to today (euphemisms are my superpower lol jk)!

EDIT 2: I see the "Enable Sound API/Access" toggle in the Gear icon, below my generation. Exploring this now.

EDIT 3: Behold the HORROR (Works in Desktop Browser) English -> Morse code with "Sound": http://asim.sh/s/160375

- tip: beware of playing long morse code sequences, there is no stopping it.

hahahaha i love it!!

sound and video generation are very very primitive compared to image gen. definitely something we want to beef up though!

:-) I was surprised when it spoke aloud, myself!

I tried and keep stuck in a loop between "Oops! Simulation failed" and "Try Fixing".

It's always the same error but it's not displayed in full: "Error: 297:3:invalid statement encou..." ('encountered' probably? but where? how? why not show the full error?)

Also, what are 'Agent' and 'Genius'? (two different app candidates?)

will take a look at this loop.

yep, agent and genius are 2 distinct pipelines we're testing.

user id is 'bambax' just like here

Cool, aSim - it's a0.dev + Expo?

yep, you could describe it like that!

Looks awesome! How do you plan to monetize down the road?

we're currently planning on adding the ability for app creators to charge users, similar to Roblox/Robux if you're familiar, and that revenue will be shared between us and the app creator

So where do the 'apps' you generate live? On my Google Play account or just inside of Asim?

currently they only live inside of aSim, but we are playing around with the idea of being able to export apps. the Android APK export is definitely doable, but the iOS side is definitely more challenging, so unsure if we will commit to it.

What about monetization? Do you think integrating ad networks or IAP and then sharing ad monetization revenue or IAP revenue with developers is a good way to go?

I’d say this is more a tool for prototypes.

You could secure angel funding off a simple prototype.

You could also make something funny and share it with friends, if it doesn’t need to be monetized.

I wouldn’t use tools like this for long lived products though.

Would like to try it out but I’m not receiving the verification code on my UK number.

we're definitely under heavy load right now - might be hitting some rate limits. can you try again now? if it still doesn't work, hit me up at dli@asim.sh or on our discord https://www.asim.sh/discord and i'll get you sorted!

Looks like many of those mobile app generators these days:

https://www.create.xyz/

https://www.tempo.new/

Seems like most (all?) are making react native apps using expo.

We’re a bit different than these since our apps are instantly deployed, not deployed through expo. So right after generation, you tap on your app and it loads and is usable, kinda like a webpage.

React native definitely seems to work the best! I think the current generation LLMs have just seen so much js/ts they can just about do anything in those languages.

This all feels like Dreamweaver + 25 years, to me.

wow I haven't heard someone bring up dreamweaver in probably a decade. brings back memories of coding on my cow colored gateway laptop :')

I think you're missing some too. I've been vaguely following and have seen very few that actually seem to have any apps on the app store and those that I found were basic examples.

yea there's a ton now that i've stopped trying to keep tabs on them. i agree that most 'vibe-coded' apps are still really, really basic, so we try to lean into that. give some cool apis that make certain things easy, and make it easy to create kinda dumb, but fun apps. the sweet spot is usually some kind of meme, or something with your friends, like https://asim.sh/@rish/s/157178/create-a-cute-gamified-app-ca...

There's at least one that generates Flutter now.

https://news.ycombinator.com/item?id=43342101

Also Lovable, which the above is inspired by!

Wonder if there will ever be a .net maui one

We need a generator for mobile app generators.

i think i've seen this prompt at least 5 times today in the logs lol

congrats on launching. how are you handling backend needs? firebase? supabse? whats good/whats missing?

thanks! we just use good old fashioned postgres running on azure, paired with a node server and blob storage in r2. i like how simple it is, and logs show up in places i'd expect without having to remember how to navigate some ui. queuing was something that took a bit to figure out correctly, but pg-boss ended up being the most straighfoward/easy to deploy on our infra.

oh man sorry i didnt mean YOUR backend, i mean the backend of the apps that you make. in the demo video you showed something about Yikyak clone. whats the backend of that?

haha oh, these kinds of clones are mostly just built on basic KV stores that we store in our postgres db! there's a couple different types of KV stores we give the app generations, but it's mostly just differing auth types (global, private, shared w/ friends).

decent solution for now. curious the tradeoffs of storing the kv in postgres vs a dedicated db. doesnt matter til the apps take off i guess!

While that’s interesting, what I’m really after these days is a Mobile App that generates Mobile Apps that generate Mobile Apps

You can never have too many mobile app generators

will be taking a note of this and putting into consideration for our next venture!

Think endless currying

Perhaps you could loop it back and make a quine, too.

hmm, kinda like a... y combinator?

I'd love to see this adapted for desktop apps. Any plans on doing that?

Ironic that I end up competing with an AI app generator for work...

haha i think it's been a great namesake!

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nice april fools joke!

This is so wild. Definitely one of the cooler uses of AI I have seen, especially for a consumer/app/game.

thank you! we've definitely had a blast building it, hope you enjoy it!

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haha no (at least not to my knowledge)! just following in gmail's footsteps of launching on april fools

Have to provide a number just to try someone else's app, hard pass.

Thx for the feedback - didnt have a chance to implement email otps (will start that now!) and even less didn’t want to figure out sign in with google/apple

Why do I need to sign in at all to view ?

unfortunately we've already been targeted by a small scale DOS attack (or wallet attack?), and account creation on our most expensive model was the only way we could solve the problem for now :/

I've worked in the anti-bot space for a while. Friction to real users is a huge cost. I strongly recommend a better solution.

We need an AI app that generates and manages throwaway sign-ups with a single click so we can use AI apps that generate mobile apps.

Wouldn't adding either of those be quite straightforward leaning on AI?

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