If you are into SIMD (Single Instruction, Multiple Data) Swift 2 has good support for it. In this post Russ benchmarks Swift's support for SIMD instructions and shows how you can use it.
Geppy from InvasiveCode shows how to use LLDB expression command with code samples and an example. Must read if you haven't used it, can't imagine debugging without it.
This is a comprehensive post to put an end to the question of whether to use Struct or Classes in Swift.
If you are still looking to add Universal Links to your app this is the blog post for you.
According to Aaron 1 out of 10 users finds an app that doesn't have Color blind mode difficult to use. He has some good suggestions on how to support color blindness in your app.
Luke suggests some improvements that can be made to Apple Watch UI, worth a read if you are designing Apple Watch apps.
If you are wondering how to use "defer" method in RxJava Dan has written a great post about it.
This is a great post on how to make animations faster over time so your app doesn't feel slow to the users. Paul even created a git repo called Quicksend to help you with it.
If you haven't yet explored the Android Design Support Library, Joe has a very well written walk through in this post with examples!
In the words of a commenter - "One of the most objective yet personalized in depth look at Material Design and iOS design I have read so far. Looking at the strengths while not neglecting the weaknesses of each."