Decreasing the iOS app size for AppStore (Xamarin)

Question

We have the big IPA (about 80 mb, having about 60 mb binary) build in latest Xamarin. When submitting this to AppStore we've got the message the the app will be unpacked for AppStore and the size will be about 140 mb (that will not allow users to download the app via cellular networs, only WiFi). We've decided to use bitcode to decrease the size of the app for downloading for each platform. So here are few questions:

1. How do you think - will it help?
2. How can we enable bitcode support for iPhone app? (we see this option in Xamarin only for TVOS apps)
3. Could you please share any ideas how to resolve this? (we've already deleted everything that is not used - assets and so on)

Answer 1

1. It will probably not help.

This is because the final result is the same: the App Store will compile your bitcode to native code, and then calculate the app size.

Compiling to native code from bitcode (by the App Store) might or might not produce native code of a different size than if it had been compiled directly to native code by Xamarin.iOS. However it will not make your 140mb app shrink to 100mb to get within the App Store's cellular download limit.

2. It's currently not possible to enable bitcode for iOS apps in Xamarin.

3. The first answer here is to make sure you've enabled the managed linker: https://developer.xamarin.com/guides/ios/advanced_topics/linker/ .

Answer 2

3. Could you please share any ideas how to resolve this?

Beside the documentation on Xamarin's web site you can watch the video of my Advanced iOS Build mechanics talk I gave at Evolve 2013 . It covers to pros and cons of most settings of the managed linker that ships with Xamarin.iOS.

You should also read about iOS App Thinning and On Demand Resources to see if they could help you for your project.