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Launch HN: Wolfia (YC S22) – A mobile app emulator you can share with a link

172 points by fabiendevos ↗ HN
Hi HN! We’re Fabien and Naren, co-founders of Wolfia (https://www.wolfia.com). Wolfia lets you share a link to a mobile emulator running your app. Developers can get feedback instantly on a feature they just built by sharing a link to an interactive version of their app. We’re starting with Android but iOS is coming soon!

Mobile app development in 2022 is harder than it should be - you can't easily change a line of code, rebuild the app, and have someone on the other side of the world see the result in seconds. Instead of the rapid iterations that web app developers enjoy, mobile app developers are stuck with pushing builds every night and waiting a day for the team to see the new code. That's if they even have a nightly build setup. Most people also only have one phone, so they can never test the Android app if they have an iPhone and vice versa.

We've been developing mobile apps for over 10 years (at Facebook, Wealthfront, etc.). In that time, the tooling has dramatically improved, yet we still found ourselves having to go and install emulators on a PM's laptop and give them commands to copy and paste on the terminal because they didn't have an Android phone. Or we would have to procure test phones and wait for a build to be pushed. We’re building Wolfia to finally make this process seamless.

Wolfia lets developers send a link to an APK (an Android binary) that's running on an emulator accessible via the browser. You can then play with the app without the need for a physical device. This dramatically shortens the feedback loop and completely transforms the dev cycle: from days to hours or even minutes.

Product managers and designers can use it to check that a new feature is being built up to their specs. Developers can use it to check if the code is running correctly. Founders, user researchers and salespeople can use it for interactive demos of the product.

We host headless (without GUI) Android emulators with hardware acceleration running on AWS bare metal instances to get high performance. We use WebSockets to make a two-way connection between the browser and the emulator through ADB (Android Debug Bridge). The emulator's GUI is displayed on the browser via an H.264 video feed, and we relay the user's touch events back to the emulator. We use WSS to make this secure.

Try it for free at https://www.wolfia.com! (you can try a demo - we used Materialistic, an open source HN app - or sign up for free and upload your own app)

We would love to hear your thoughts, ideas and feedback!

74 comments

[ 3.0 ms ] story [ 128 ms ] thread
rareitem
Very interesting! Do you plan to support ios apps in the future?
narenkmano
Yes, absolutely. It's on our roadmap.
jimkleiber
Wow, this could have been useful back in 2012 when I was building an Android app and hard-coded a web demo in JS. I still feel proud of it, but probably would have preferred this route :-D
ushakov
how is it different from appetize.io?
fabiendevos
Good question, it's similar indeed but in our experience Appetize is significantly slower. We are also going to focus on collaboration between team members as opposed to testing and training.
ushakov
you mean the free tier? with bigger tiers you can reserve the device

also I don't understand the 15 minute session timeout

what happens when the time runs out?

fabiendevos
Yes our free tier should be more performant than theirs. In the future, we want to differentiate on collaboration features. For the session limit: we haven't added it to the pricing page yet but we have an option to pay as you go which removes the 15 minute timeout.
mwcampbell
Congratulations on your launch! Interesting product.

What happens if a user needs to share the emulated app with a colleague or prospective customer who requires accessibility tools such as TalkBack or VoiceOver? Can you run tools like that in the emulator alongside the app? I'm guessing this would be straightforward for Android, but maybe not so much for iOS.

narenkmano
Great question. We don't support audio (including TalkBack) at the moment. But it's very high on our roadmap.

For iOS, we plan to support similar features and we will explore if we can use the Accessibility Inspector tool to support VoiceOver.

WaitWaitWha
Congrats on your launch.

What are your distinguishing selling points (besides cost) compared to Amazon Device Farm[0]?

[0] https://aws.amazon.com/device-farm/

fabiendevos
Amazon Device Farm is mostly focused on testing on many different devices. We are more focused on collaboration between team members. We want to make it frictionless to share a build with your team, and get feedback from them with comments, redlines, and short clips. We're building towards this vision as fast as we can. :)
honkdaddy
Love this idea. I’ve been sending screencasts to PMs for years now, something like this would have saved me dozens of hours over the years.

Since I’m mostly an Apple dev, when do you see yourselves supporting iOS as well? I’ve seen other companies try the “Mac/iOS in the cloud” thing and I’ve yet to see it work perfectly so I’m curious what your vision is to make it a great experience.

fabiendevos
Thanks! We are hoping to support iOS within a couple of months. We want to have the same level of performance as what we achieve today with Android. I am curious what didn't work great when you tried iOS in the cloud options in the past? Just performance or something else as well?
dfgwt
Looks cool, but using it from another mobile device is very slow. Or maybe it's latency to the servers hosting the emulators, I'm not sure. Is there a way to see the ping time?
fabiendevos
Yes it works on mobile but is a bit slower, we want to continue to improve performance there. It's reasonable on a Pixel 6 pro, I'm curious which phone are you using? We'll look into the ping time.
dfgwt
It's a Samsung Galaxy A52s, I tried Firefox and Chrome.

Also used a TCP ping app to check what seems to be the demo server - node1.wolfia.com? Average was around 160ms, ranging from 70 to 300ish, so I guess that was the real issue!

I'm located in UK and using a 4G network. Might try it again tomorrow from work and see how it compares.

fabiendevos
Ah yeah that's probably why, our servers are only on the west coast for now, we'll add more locations in the future.
Rebelgecko
FWIW the demo runs really well in my pixel 4a, although some of the text on the page covers up the navbar. Love how low friction it is though!
dfgwt
Agreed, I'm impressed by just clicking a link and seeing the app there to use, no messing around. Good stuff.
aneesv
This is a great service! Do you plan to provide an API to upload new apps?
narenkmano
Thank you! That's the next item on our roadmap. We plan to create a public API and gradle plugin to automate link creation.

Our vision is to have a stable link for your app that links to the latest version of the app so that people can quickly find and interact with it.

6figurelenins
> mobile app developers are stuck with pushing builds every night and waiting a day for the team to see the new code

That doesn't ring true. TestFlight / Play Store uploads are typically available within 15 minutes.

Still, it's nice you're solving deployment overhead. In particular, my team needs side-by-side installs of the live/prod build and dev/staging build.

It's double the headache to stand up a store listing and comply with policy changes, just for an internal distribution channel. Save me.

fabiendevos
Totally true that TestFlight / Play Store uploads are available within 15 min, but in our experience, nobody wants to push to those platform that frequently, and force many upgrades of the app every day, so instead they do nightly builds at best. More importantly, it doesn't help if people don't have the right phone. We would love to help you with this use case, does an emulator in the browser works for you or do you need to install to phones?
6figurelenins
For me, an emulator solves the 80% case: I'm soliciting quick feedback on specific changes. I'd happily use one as TestFlight for dev builds. I'm optimistic my users (my team) would find it more convenient, less interruptive. I'll ask them.

The other 20% is stuff that doesn't work in an emulator. Usually Apple, certificates.

It's enough of a minefield that QA means real devices, unfortunately. Used phones are vastly cheaper than "false alarm" bug reports.

> in our experience, nobody wants to push to those platform that frequently, and force many upgrades of the app every day, so instead they do nightly builds at best

If my team's big enough for daily builds, we have continuous deployment (Fastlane or similar). Strictly speaking, the pain is the build step (slow; can be flaky), not pushing the artifact.

I hope this is helpful. Feel free to dig deeper, I'll keep an eye on this thread.

narenkmano
Thanks for the feedback, and let us know if your team is interested.

For the deployment, wolfia allows you to share builds before they are merged and solicit feedback from your team earlier. If you think about it, the feedback loop is much faster in practice than waiting for deployment and then getting the feedback. However, I do agree that the build step is a pain! Our vision is to bring the same experience web developers have to mobile essentially, so we'll take a stab at it in the future :)

leoqa
I think many commenters here haven’t been a mobile engineer at a large company- most engineers don’t have creds to manage the app for the face of a +50B company.
liminalsunset
Underrated use cases (which I hopefully don't ruin by saying out loud):

-Share a browser session; someone can log in and let someone else do stuff without having to share their password.

-Burner phone to install garbage, or untrusted apps on that "you only need once" or that you just need to use to screenshot a coupon etc.

-Burner phone to access Facebook or TikTok with, with no private data risk

-US IP address to get around geoblocking

narenkmano
Those are some great use cases! We already support the sharing sessions with multiple users. You can tap on the copy link to share control button on the bottom right of the emulator page and send it to someone to share your session :)
fudged71
This would be fantastic for executive assistants
fabiendevos
Interesting, what use case do you have in mind for EAs?
forrest2
I've used an emulator in the past for GPS spoofing too. Obviously useful for testing and what not but also for location based apps / games / etc.

Tangent: IIRC Pokemon GO (and probably other more professional usecases for GPS spoofing) mitigates spoofing via a variety of techniques

fabiendevos
It should be fairly straightforward for us to provide that option.
liminalsunset
It appears that the keyboard on a computer does not work in the emulator on either Chrome or Firefox on Mac M1.

I think it would be useful to be able to use the keyboard to input text.

narenkmano
It isn't enabled by default. But, if you click on the keyboard icon on the control bar to the left of the emulator, you should be able to use your keyboard. This is something we plan to improve.
TimCTRL
This is really excellent. A quick one, is there a plan for us to select a particular android device? This would be particularly useful for debugging apps.

Unlike in the IOS world, the Android market is so saturated with devices, you may not know how your app (camera feature for example) will behave on a Tecno phone.

narenkmano
Yes, we plan to support different devices and API levels soon.
rock_artist
Indeed. With Android my biggest problem is devices behave differently and even just changing Andriid APIs discover issues.
tpmx
Seems very well executed. Congrats!

When I last had a need for something like this confidentiality was a major concern (it was at a small-ish but publicly traded company). Not quite at the level of needing signed contracts, but at the same time something more than a random web service someone unnamed threw together would be required.

I notice that you haven't put your names and backgrounds on the site - that would help in building credibility. Demonstrating the YC backing would also help.

narenkmano
You can check out our security practices here - https://www.wolfia.com/security

Agreed with building credibility. We'll add our names and backgrounds along with the YC backing on our website soon.

Also, we plan to support an on-premises option in the future.

krageon
Names and pictures don't help in building credibility, because you can put any name you want and any picture you want online. What is that supposed to prove?
tpmx
When you have a name, some background and perhaps a photo you can do some superficial background research using open resources. I do it all the time. Is it foolproof? no. Is it better than nothing? yes.
bluelightning2k
What a brilliant idea. Well done! Must have taken some real tech muscle too.

FYI: the first thing I did was click your demo app and try to read this article. I couldn't. Maybe this is because of your launch traffic spike but you should know.

narenkmano
Thank you! You should be able to try it out now. If you can't still, pm me at naren@wolfia.com
tauntz
Piggybacking on this, in case you're looking for general purpose blazingly fast Android emulators to run your tests on, then hop over to https://emulator.wtf

(I'm not using the term lightly here - we're multiple times faster and more stable than Firebase Test Lab and you could be running your full test suite in a couple of minutes, instead of hours)

narenkmano
Looked at the website. Looks pretty cool. Will check it out!
mleonhard
Nice. I think you should do your own Show HN post. Your website needs your name and company info.
TruthWillHurt
15 min/session, even on highest payed tier?

I smell AWS Lambda :D

narenkmano
We're not running on AWS Lambda but we had the limit in place because our servers are pretty expensive to run. We are planning to add to the pricing model a pay as you go option which will allow for us to provide unlimited time per session.
mike_d
Your customers don't care _why_ your service is unreasonably expensive.

Would you go to a dry cleaner that charged you $50 a shirt because "I fly the shirts to my brothers shop on the other coast to be cleaned"? Of course not.

I can think of no reason why you need to be on AWS vs a dedicated server or a stack of used Dell servers in your garage.

narenkmano
We did consider the option of building our own servers but getting started with AWS is much easier because we don't have to maintain our own hardware, so we went with that. This allows us to move much faster and deliver features that users want instead of optimizing costs.
TazeTSchnitzel
Is iOS via the iPhone Simulator?
fabiendevos
We do not support iOS yet but yes, the plan is to use the simulator.
Rodeoclash
Heh, I was in an incubator in 2012, ten years ago! Where they managed to do this with IOS apps:

https://web.archive.org/web/20121203101645/https://www.kickf...

fabiendevos
Oh nice! Looks like it was mostly used as a marketing tool which is a use case we're considering. Do you happen to know more about them?
krohling
I came here to see if anyone mentioned Kickfolio :) They ended up changing their name to App.io at one point. Smart, great group of folks. Closed down back in like 2015.
smashah
Nice! Do you plan to support virtual camera (e.g I give it a stream to use for the camera)
narenkmano
We can look into it. Adding it to the backlog.
awwx
fyi - some feedback on your website, in case it might be helpful.

I clicked on it first before I read your description here.

Looking at your website, I had no idea what you were doing.

I don't even see "mobile" mentioned anywhere.

The headline says "Turn your app into a link"; I skipped over "APK", and read "get a shareable link to an interactive version of your app"

Um, isn't my app already interactive?

I scrolled through the rest of the page, and still had no idea what you did.

Then I came back here, clicked on "comments", and read your description.

Which was great. Oh, you give a link to a -> mobile app -> emulator -> which can be easily tested without having to get it on an actual phone.

If you took your description here and put it on your home page, it'd be much better :-)

fabiendevos
This is good feedback, we will definitely update the description. Is "A mobile app emulator you can share with a link" clearer as a first sentence?
kytazo
Amazing! Props to the creators, incredible idea.
kytazo
Allowing for complementary sign up options besides google would most likely encourage more people that use no google services evaluating the platform, myself included.

Something to keep in mind in case you notice more people bouncing off your register page more than you'd normally expect.

narenkmano
Good point. We have other options for sign up pretty high on our list. We wanted to launch the MVP as soon as possible to hear feedback so that we can talk to customers and iterate on the right thing. We'll prioritize this higher :)
numlock86
Awesome stuff. I tried the demo ... from within the demo. :)