On PC or Mac, you can easily reboot it using a couple of mouse click. But there is no direct way to reboot your iPhone. A hack called GPower targets to On top of the built-in “Slide to Power” function, GPower is a new cydia application that adds “Slide to Reboot” and “Slide to Respring” features to iPhone.
Normally, to reboot your iPhone, you’ll need to first power it of and then turn it back on again. With GPower, it adds options to let you slide to reboot.
To install GPower, launch Cydia and tap “Search” button. Search for “GPower” and install it. Once installed, you can simply press and hold the “Power/Sleep” button to invoke it.
Same as other hacks, GPower only works on jailbroken iPhone and it also supports iPhone 3.0.