Some apps will conflict with each other in Cydia and Apple. Best practice is to download only one app at a time, and use it for a while before downloading another one. Oh, and by the way, keep a list of the apps you download from Cydia by date and time installed. That way, if you have a problem, you can check your list and delete the last app installed. If a new app crashes in Cydia, your iDevice will probably reboot into SAFE MODE, tap REBOOT, and try again, often that will clear the problem. I it doesn't, when Cydia comes up in SAFE MODE again, select Cydia. When Cydia loads up, goto MANAGE and delete the app and Reboot again. Every thing should be back to normal, if that app was causing the problem. If not, delete the next app on your list of apps installed. Repeat as necessary. You shouldn't have to do this most of the time. Download "Cydelete" from the Cydia store and then for apps that have an icon, you can delete them just like Apple apps, Hold till they wiggle and tap the X in the circle at the top left of the apps icon. This is a lot easier than going to Cydia > Manage > ......