Talk I gave at VoxxedDays Belgrade 2015 conference.
Video (in English): https://www.youtube.com/watch?v=rft2KzD4i0k
I look at the Watch app from two angles:
1. Product Manager
How to brainstorm and decide do you need a watch app at all and if yes, what it should be
Issues and challenges in both iOS8+WatchKit 1 path and in iOS 9 + watchOS 2 path