It's not free, sadly. I think it's $5.99. There is a 7 day trial. It's the only app I've considered buying, but haven't yet. Perhaps when there's a half-off sale or something. I hear OS5.0 is going to have the same options, maybe, so some people are holding off on purchase.
You might want to try the trial version at least. It's really quite handy and way better than the 15 minute flashing red light that's standard.
berrybuzz will alert you to when the phone is charged with a ring/notification tone of your choosing and/or by a flashing light of a color you specify for an amount of time you specify. good app.
