Rakkup Guide Book App
Here's an app that uses GPS locationing to get you to your climb. Not sure how it works with elevations... Works offline. http://www.rakkup.com/
The next step up, which I had thought about was a virtual reality overlay. This is similar to the peak finder app. The idea here would be to overlay route arrows onto your camera's real image. Therefore you would point your camera at the cliff you are at and it would highlight the routes and spit out some extra info.
The data crunching is too tough for this. Tree foliage at different times of years confounds the vectors you need to store in order for an object to be recognized. This type of augmented reality uses GPS locationing to filter the database of all possible locations. It then uses "edges" to match what you see to what has been loaded into your virtual reality server. It then spits out the augmented reality layer onto your camera's image. Layar is one of the basic tools for this.