The application is of course totally free and available on the GooglePlay: play.google.com/store/apps/details?id=com.mouren_olivier.reboot_this_phone
I made this app for a friend at the beginning and especially to pratice in Android development : this is my first real and functional application I made with the Android SDK so I wanted to share it with many people as possible!
Technically, the application intercepts incoming messages before they go in the phone's SMS Inbox and if it is a "=" (or repeated "=") : the SMS received is deleted which avoids the reboot!
So it's pretty simple and it would help a lot of people!
The protection doesn't work on Android "KitKat" 4.4 and ulterior because Google change their "SMS Application" systems (Developpers must know this "problem"), my application could not delete intercepted message without to be considered as the default SMS application.
I hope I helped you and don't forget to share with your friends and to comment here or on the GooglePlay !