This fairly simple Android app adds a layer of safety for folks who often misplace their Android cellphone while it’s in silent mode. Called RemoteRinger, you assign a special code to the phone as well as a designated caller number. You can then send an SMS from the designated phone number. Bang: your ringer is back on.
The app is free and available here. It’s brand new so there are bound to be some bugs but it seems like a good enough idea.