Gaining remote access to a phone isn't only for super hackers and spies. There are plenty of times when the average smartphone user would want to have remote access to their device.
Maybe you left your Android phone at home and coincidentally forgot to stop farming coins in your Plants vs. Zombies zen garden. By the time you get home, your phone will be dead. Maybe you forgot to enable Wi-Fi on your phone and let your friend borrow it to watch Netflix or something. Data charges through the roof!
What's the fastest way to fix this problem when you don't have hands-on? Remotely shut the damn thing off, and if you've got a Samsung Galaxy Note 2 or other popular Android device, it's as easy as sending yourself a text message.
The app is called Remote Turn Off and was created by developer RavinduSha. It works by executing the power down command via an SMS message—you send an SMS containing the phrase power#off to your device from any number and it will automatically shut down.
In order to install this app, the device must be rooted so you can access some system files. You will need to flash this .zip file or just place the APK into the /system/app folder manually and set the correct permissions. After the initial install, send the SMS phrase power#off to your device and it should ask for root permission.
And that's it.
Unfortunately, you can't change the text command, but that's no biggie. And if you can install this on your friend's Android device, imagine the prank possibilities! Your friend is sitting on the couch shooting for 3 stars on the final stage of Angry Birds Space and you remotely shut down his device. Awesome.
There is no folder or program file, so they will never know it's there, unless they know their stuff.
If you want to do more than just shut down your device remotely, look into aeGis, which lets you remote wipe your device, lock the screen, sound the alarm, and more (though, shutting down the device is not an option).