Mike from Crashlytics and Fabric here.
You can now capture logged NSErrors in your iOS, tvOS, or OS X app. You want to use:
[CrashlyticsKit recordError:error];
or
Crashlytics.sharedInstance().recordError(error)
This will let you capture a fair number of logged NSErrors per user session. These are only sent on app relaunch. Logged errors errors are grouped by the error domain and code. This means error issues can span many different call sites.
See Documentation