As I notice, apple watch will turn its display off (meaning call method WKInterfaceController.didDeactivate). However, I don't want this. Is there anyway I could force the display stay on within my app's life cycle? Mine is Watch OS 2 Beta 4
Check out the answer on this post: Keep Apple Watch awake
No. You can however tell your users to use the Setting inside the AppleWatch app "Show session app" instead of "Show clock face" (I´m sorry for the translations, my watch is on Swedish. Correct if wrong please.)
This will activate your app whenever the wrist is raised again.