We've been using Appsee for a couple of years now - we find them the best for detecting mobile app ux issues and small bugs we might not have otherwise known about. They give automatic insights for problematic screens and link most of their standard analytics like conversion funnels with additional session replay functionality.

The ANR and the'killed by user' filters have proved very useful for us and the touch heatmaps are great. You get a nice breakdown of all gestures made on a particular screen (taps, swipes etc) and Appsee also automatically identifies when an action has been unresponsive.