I went to iOSDC 2017 on September 17th. This conference held for iOS developers on September from 16th to 17th at Waseda University.
I heard these sessions:
飛び道具ではないMetal This session told us how to use Metal to render an image on display. What most interesting is that to draw a picture without Metal is faster than with it.
I had no time to listen to all the sessions this time. And I haven't had knowledge of developing iOS. So There were some sessions I couldn't make sense. Now, I've been developing an iOS app with Swift!