If you are in Safe Mode, I'm going to assume that you are jailbroken. Safe Mode it telling you that you have an app that is crashing, and have downloaded an app and, it's a bad install, or, and app conflicting with another app. While in Safe Mode goto "Cydia > Manage > Packages",and uninstall the last app you downloaded before you went into Safe Mode. If that doesn't work, delete the next to last app you installed, etc.
