When comparing Countly vs Crittercism, the Slant community recommends Countly for most people. In the question“What are the best mobile bug and error reporting tools for iOS/Cross-Platform?” Countly is ranked 1st while Crittercism is ranked 3rd. The most important reason people chose Countly is:
No need to use another SDK.
Ranked in these QuestionsQuestion Ranking
Pros
Pro All in one crash, analytics and push notifications
No need to use another SDK.
Pro Continually updating real time analytics
Countly pages are updated in real time without needing a page refresh.
Pro Try without signing up through open demo
You can try it out without signing up at all by playing around with their demo.
Pro Very fast interface
Transitions between pages on the Countly web interface is nearly instant.
Pro The UI is extremely user-friendly
Crittercism's dashboard shows all the information needed for finding and fixing bugs. It displays all running threads at the time the crash occurred, memory usage, battery level, disk space, sdcard space and other important information about the device.

Pro Supports All Mobile Platforms:
iOS, Android, Android NDK, Windows Phone, Unity, Xamarin, Appcelerator, HTML5

Pro Used by many big companies
Crittercism is used by Netflix, eBay, Nike, etc.
Pro Free plan available
The Free plan includes up to 30000 Monthly users, data retention for upto 30 days and Email support. So if you have a small to medium sized app, you can go for Crittercism.
Cons
