(removed the erroneous steps to reproduce...)

Is anyone else experiencing high CPU usage on iOS hardware? I get about 15% usage on iPhone 5S when our app is in foreground. There are no log messages that would suggest what is going on. (There are log messages when you interact with the app. But there isn't any constant network activity, timer callbacks, GPS, etc. going on when the user isn't interacting.)

Kind of a long-shot, since a freshly-generated app doesn't do this, so it must be something our app is doing.

I'll post some Profiler details later, in case somebody else has had a similar issue and might recognize it. It's difficult to pin-down because it is system services that are taking up the CPU time.