BugSense is a tool that collects and analyzes crash reports from mobile apps. Supports Windows Phone 7, Windows Phone 8, Windows 8, HTML5 Android and iOS.
The bugsense tool is split into two parts. One client part that is a framework/assembly/package that you can reference and easily hook up to the unhandled exception handler for the respective platform.
The other part is the server where you can analyze crashes. Most importantly sort them by occurrence for easy prioritization. It's also very easy to see the stacktrace in order to be able to fix crashes.
Bugsense is free to try.