PowerTool is an application that allows you to respring and reboot your iPhone. THe application will open to the main page in which you have the options to; Set Language which will restart your iPhone without going to the lock screen, Restart SpringBoard which will restart your SpringBoard bringing it to the lock screen and Reboot which will bring you to the boot logo screen.
When I tested the application, all the options work exactly as they should.
PowerTool is available through the iSpazio source.