Open Source Apps

One of the very exciting trends I’ve been seeing recently is the open sourcing of actual iOS/OSX apps. Here are a few examples (feel free to add more in the comments):

  • Artsy: Explore, collect, and share more than 100,000 high-resolution artworks
  • Gulps: An iOS and Apple Watch app for keeping track of your daily water consumption.
  • Project-RainMan: Open Source Weather App created with Swift and powered by
  • PebCiti: A simple iOS app to show the nearest available CitiBike NYC dock on your Pebble (opportunity here to contribute a Watch App version)
  • Parties for WWDC: WWDC hit parties app
  • WWDC: WWDC app for OS X
  • WatchSnake: A clone of the game Snake for Watch (don’t think it’s going in the app store, but I really enjoyed playing it on my wrist anyway)

I like to track my daily water consumption, so when I got my Apple Watch, I immediately downloaded Gulps. However, there were a few small things that bothered me about the Gulps Watch App. As a developer, I, of course, would normally just start working on my own app that is only slightly different than the other app – I just want that one feature!

Well, since Gulps is open source, I just went ahead and submitted the fixes to the two things that bothered me most. And voilà, the changes have been merged!

I cannot overstate how empowering it is to contribute to an existing app I actually use. The small changes I made will be in the App Store, and I didn’t have to go through the whole process of creating a whole new app, just to most likely quit finishing it because I don’t have time to finish / maintain it in the long run.

Of course open sourcing your app is not something that’s possible for a lot of companies or startups, but if you have a passion project that you’re doing just for fun, consider open sourcing it! We as a community, can create powerful and beautiful apps together.

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  • FlexMonkey

    Hi Natasha,

    Great post. I have two open source apps in the App Store: Emergent is a swarm chemistry simulation: and ReDiLab is a reaction diffusion simulation:

    They’re both academic-ish apps based on other people’s algorithms, so I think it would have been wrong, wrong, wrong to keep them closed source. Although nobody has submitted any PR’s against my code, I’m hoping that somebody somewhere has found the fact I’ve open sourced them somewhat useful.

    Best wishes,

    Simon (

  • PJ Gray

    I have two open source apps on the app store right now.

    The first is OpenPics It is an image searcher & viewer optimized for easily adding other sources of images. For example, currently I have the Library of Congress, New York Public Library, Flickr Commons, Boston Public Library and even a couple sub reddits. It is fun to hack on occasionally, but unfortunately I haven’t done as much as I should lately. I don’t think I even submitted the iOS8 version yet. 🙁

    The second is just a weekend hack called MultiMeer It lets you view all the currently live Meerkat streams at once. (Which, lately, aren’t that many…zing). It is a good example of how to read & hack on HTTP live streams and get them playing in a collection view.

    Neither is particularly designed super well or anything, but they are great to have as a testbed when Apple releases new technology. I was thinking of rewriting OpenPics in Swift…got pretty close last WWDC but ran into some collection view issues at the time.

  • andreamazz

    Open source projects for me are the best way to remember why I love this job so much, even more so when other devs decide to contribute to them… it’s a lot of fun to see other points of view and learn something new.
    I spend a lot of time developing iOS OSS libraries, but having a whole app open sourced was something new for me, and I encourage everyone to try it, we just need to get over the impostor syndrome and stop caring for secrecy 🙂
    Thanks again for your contribution to Gulps (BTW, I hope to submit the update soon, I need to get over some issues in the archiving process :D).

  • Doug Tabuchi

    I ran into the same thing with
    There was a feature I wanted and I was thrilled to be able to add it myself.

  • Thank you for the post! Waiting for more open source projects 😉

  • Miroslav Perovic

    I have open source application at This is microcode emulation of legendary HP-41 calculator. This is OS X & iOS application.

  • Hi, I released yesterday my open source app for iOS written in Swift that show the average review times for iOS and the Mac Apps using data crowdsourced from AppReviewTime (