[Q] Single-app ROM (alarm clock)

Hey everyone,

I'm not an Android developer, just a user who knows how to flash a ROM.

I use Gentle Alarm as my clock, and I want a way to have just Gentle Alarm without any other apps running, and without even being able to run anything else. Basically, I want to convert my smartphone into a dumb alarm clock at night, and make it so that I have to reboot it to start messing with email, twitter, etc.

The reason I don't use a regular "dumb" alarm clock (which is ideal for me, really) is that I need something that vibrates and doesn't ring.

Any ideas?