Is there any way to enable the ringer ONLY for a particular caller/group of callers? Is there any way or app that will take a phone that is normally on silent/vibrate, and enable the ringer for a selected group of callers?

My wife is notorious for leaving her phone on silent, and there have been several emergencies where I could not reach her because she couldn't hear/feel her phone ringing. I'd like to have a way so that when I or any other family members call her, her phone will ring, even though she has it on silent/vibrate.

I've read that the app "Locale" may work, but they offer no demo for their app, and I'd prefer not to spend 10$ if it doesn't work. Their dev hasn't responded to the email I've sent.

Any ideas or methods would be very much appreciated.
Have you tried WhoIsIt?


  
  Setup different ringtones and vibration patterns for SMS, MMS, Google Talk, Google Voice, and K-9 for each contact