Ok, I've seen people mentioning this over and over in multiple threads. This may not work if there is a different bug from a bad tweak that causes a boot loop, but, it does work for the one caused by the jailbreak itself. SYMPTOMS: You have Restarted your device (either after installing a package or via something like NCSettings)...the device fails to boot, getting stuck at the Apple logo. SOLUTION (well, workaround): If you are near a power cord, either connected to your computer or wall, or car, whatever...plug in the phone, then do a hard reset (Hold home+power). Your device should reboot successfully. If you are NOT near a power cord: Do a hard reset (Hold home+power). When the phone starts the reboot, immediately press and hold the volume UP button until the apple logo gets brighter. Then you can let go. Your device will boot up in safe mode with your tweaks disabled. Then shut down the phone (not restart or respring), and turn the phone back on. You should be good to go now. If the above DIDN'T work, then your reboot loop is likely due to a bad tweak.