How to Fix Stuck at Apple Logo Endless Reboot Trick in iOS 9: If your device is currently stuck in an endless reboot loop, there is a very effective way to go about fixing this problem without having to do a full restore using iTunes that works for jailbroken devices.
This usually happens due to have a jailbreak tweak or two having problems working together, or perhaps a corrupted application.
Step 1: Hard Reboot your device: for that you will have to do is hold the Power button and Home button together to power your device off.
Step 2: Once the device shuts off, you can take your fingers off the button. Next you will want to press the Power button to power your device back on. Once this happens you will want to click and hold on the volume up button on the device. This will allow your device to boot up in Safe Mode. It will take a minute for your device to boot up (in safe mode).
Your device will boot into Safe Mode, so all of your Jailbreak tweaks will be completely disabled. Slide to unlock your device just to see that you can do anything you want on your device. Now you will need to figure out why your device is in an endless loop so you can correct the problem.
If your device is crashing you also have a good option: install CrashReporter tweak. It will show you the apps that are provoking the crash.
One last way you have to fix a lot of problems is to restore your device without updating. Then you can do a clean jailbreak of your device again and install only the main tweaks.