reBoot is a very simple and light app that allows you to restart, shutdown or switch to recovery mode your phone or tablet in only one simple clic.
You need to have root access rights on your device.
The commands used are :
"reboot now" for restarting
"reboot recovery" to go into recovery mode
"halt" to shutdown your device
If it doesn't work for you please test the commands in the terminal and contact me !