Starting with a demo to show you screen zoomIn and zoomOut, this is rather very easy. THere will be more camera functions that would allow for creating an app/game that needs a camera like functionality.
Some of the things that you can do with it would be
Pan, Track, zoomIn, ZoomOut, dragPan amongst other things
the Video Demo ->
This will not be for sale, no one wants to buy stuff anymore, so here's for inspiration only