Super cool! I've been thinking about making an app that does something like this - point your phone camera at the mountains and based on your GPS and compass heading, overlays the name of each peak it sees.
This app exists. Check out ViewRanger: http://www.viewranger.com/en-US
The app is free for both IOS and Android. Many maps are free (open street, open bike, etc..., and USGS 1:24,000 for contiguous USA, Hawaii and Alaska is $24.00
Maps can be downloaded to your device for use off line.