Park Güell Tour App:
This app provides information about all the important parts of Park Güell. While walking through the park you can use it to find your position on the map (a device with GPS is required).
The app includes the history of the park, a short biography of Gaudí, and essential information such as how to get to the park, whether or not there is an admission charge.
Even if you can't visit Barcelona, you can 'virtually walk' through the park with a panorama of each important place in the park.