itunesconnect App - Revert to previous version

Question

I released an update for my App and it was approved. It was approve despite the fact that it included a serious localization bug where most users are getting the wrong language.

Answer 1

Preface: I agree with the other posts here that you can't perform a rollback through the iTunes Connect itself. Even if you could, you'd suffer the lag time it takes for users to update to the rolled-back-version. But that doesn't mean we can't still rollback apps.

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Retroactively, you cannot rollback an app. Proactively, however, you can instrument your app to enable future rollbacks after a build has been released and installed.

High-level steps:

• Build each version of your application as a framework
• For each release build, include both the current and old framework versions
• On app boot, decided which framework to load and execute (include sane defaults)
• When you want to rollback, update the cached values across all user devices and wait for the next app open.

This strategy uses similar mechanics to feature flags which are commonly used to enable/disable features without re-releasing. However, in this case, you're "feature-flagging" your entire app version.

Is feature flagging between embedded libraries against App Store Guidelines?

No. Embedding two versions of your app into one release is not against App Store review guidelines:

4.7 HTML5 Games, Bots, etc.

Apps may contain or run code that is not embedded in the binary (e.g. HTML5-based games, bots, etc.), as long as code distribution isn’t the main purpose of the app, the code is not offered in a store or store-like interface, and provided that the software (1) is free or purchased using in-app purchase; (2) only uses capabilities available in a standard WebKit view (e.g. it must open and run natively in Safari without modifications or additional software); your app must use WebKit and JavaScript Core to run third-party software and should not attempt to extend or expose native platform APIs to third-party software;

Similar to feature flags, all code that you plan to run is included in the binary that you submit for review. What's more, as long as you are rolling back to releases that Apple already reviewed and approved, you're not breaking the spirit of the guidelines.

Does this hurt performance?

I've profiled this approach against many of the popular and heavy open-source iOS apps including Wikipedia, Signal, Firefox, etc. You can be smart about deduping assets and shared libraries, resulting in a sandwiched-app-bundle size of about 1.2x the original size (really just depending on how much code you changed). You also incur about a 50ms startup cost when choosing which version of the app to boot.

IMO, both time and size increases are worthwhile in return for the ability to selectively rollback users experiencing issues while you take time implementing a fix.

Do real apps do this?

Major apps feature-flag between dylibs all the time when launching new features and optimizing performance. I have also heard of major tech companies using this app-level pattern for their largest releases. I have a personal app in the App Store using this pattern, and I have helped other developers do the same.

How can someone do this for their app

If you are comfortable going deep on the Xcode build system, you can follow the steps outlined above and with some fiddling, start feature flagging your app version on boot. Note that you'll also need some form of caching and a server endpoint to update the on-device flag.

The implementation described above is also exactly how screenplay.dev implements iOS rollbacks. The tool:

• Adds two build targets to your Xcode project, one for building the framework version, and one for bundling the final release build.
• Serves as a repository for your old app build versions.
• Provides a web UI for toggling live versions.