How to find which apps are draining the battery on an iOS device in iOS 10?
Previously in iOS 8 you could go to Settings > Battery to see a list of apps with a percentage number for rating how much battery they were responsible for using, as shown in this posting. Gone in iOS 10.
I found the Question How to check what causes iPhone battery to drain out?. But that Question and its Answers do not really describe how to identify particular problematic apps.