I have released the source code for the HuhX Map Framework on GitHub. This is a (skeleton code) image/map engine that supports the use of multi-touch gestures to scale images accordingly. The HuhX Map Framework also supports custom menu dialog and audio playback in the background.
Applications such as Dragon Geo and Cid’s Aerial Tours utilize the HuhX Map Framework engine. If you are interested in developing Android applications that utilize image scaling and multi-touch gestures, feel free to take a look at the HuhX Map Framework code!
The open source code for the HuhX Map Framework can be found here: https://github.com/huhx0015/HuhX_Map_Framework/tree/master