[dmishe]

iOS apps are shipped as fat binaries, so for one, part of that 100mb app is duplicated slices of binaries for armv7, arm64 and possibly, but not likely, armv7s.

Android apps enjoy bytecode that is getting JIT-ed on install.

[dgallagher]

Apple has introduced App Thinning in iOS 9 apps which should cut down on their size:

https://developer.apple.com/library/watchos/documentation/ID...

[azsromej]

The feature was recently delayed, but it should help once it's ready

[notNow]

Is there any technical justification for this or it's purely economical/financial?

[dmishe]

For what, fat binaries? That's pretty much what Mach-O format had from inception under NeXTSTEP, and survived until now. As it was said in the sibling comment, iOS 9 is introducing a way to cut exactly the slice you need for a particular device.