FLEX - An in-app debugging and exploration tool for iOS.
Chrome Mobile DevTools - Mobile Debugging Tools
Bugfender - Cloud logging for your apps, not only crashes matter
Bugsee - See video, network & logs leading up to bugs or crashes
Instabug - The top apps in the world rely on Instabug for beta testing, user engagement and crash reporting.
Spark Inspector - Spark Inspector is a runtime debugger for iOS