Many of them might have faced this problem with their iPhones or the iTouch. When ever we jailbreaked our devices and then we go for an unlock, After the unlock we reboot our device. While rebooting the device we might face this problem i.e we get struck over the Apple symbol, this is a genuine problem. Most of them had complained me about this problem. We happen to face this problem mostly when we are rebooting the iDevices, The problem is that the iPhone isn't having sufficient battery so it gets struck up at the boot screen.
SOLUTION: Plug in the charger and it soon gets the boot screen on its screen now hold the home button and the lock button for 10 seconds till you get a flash on the screen and leave both the buttons and let it charge for a min of 20-30 depending on your emergency of usage. I suggest to let it charge for minimum of 20 minutes. Later start your iPhone it gets fix over this problem.