After switching to Xcode 7, app size grew from 9 MB to 60 MB, is there a fix?

Solution 1:

Most likely caused by BitCode, I have seen the same growth however once deployed from the App Store the app size hasn't actually grown.

You can disable BitCode in your app and the other targets as well and you should see a shrinkage.

Solution 2:

I've been testing a lot of settings and combinations and it seems the file size of bundles created by Xcode 7 vary a lot depending on both the device and the version of iOS. Also, the TestFlight builds are now huge compared to before, but the good news is that once on the App Store there hasn't been a huge increase (although I am seeing about 1–2 MB added to the bundle size compared to before).

Here's a few samples to show variance between TestFlight, App Store and devices:

TestFlight, iPhone 5s on iOS 9.1
35.6 MB

TestFlight, iPhone 6 on iOS 8.4.1
70.1 MB

App Store
11.8 MB

The App Store size was identical on all devices I tested. I haven't tested it on iPhone 6 Plus though, it's very possible that the bundle size would be larger since it uses @3x assets.