Jailbreaking your iOS device feels like you've just opened a magic box, but with great power comes great potential to screw things up. CrashReporter is a free app that helps you identify a problem, should one arise, so you can neutralise it and get things back to normal.
CrashReporter is a free download in Cydia, so just search for and install it like any other app and you'll be ready for when disaster strikes. If you do have a crash, chances are you'll boot into safe mode and your homescreen will look like it exploded (especially if you have lots of folders). This is when you want to open crash reporter and check the logs.
CrashReporter does more than feed you crash logs, however, and will actually suggest possible culprits. Use these suggestions as guides, and then go into Cydia to manage your installed packages. Chances are the crash is the result of something you installed, and you can simply view the package page for the potential offender, tap the Modify button, and remove it from your iOS device. Once you do that, restart and if you're not in safe mode anymore the problem has been solved.
If you haven't jailbroken your iPhone yet and want to, check out our always up-to-date guide to jailbreaking your iPhone for a full walkthrough.