I'm liking this. If you're wondering about the paid version, it does seem a little more responsive, and claims to be "ad free". I didn't see any ads in the free version to begin with, but it's a dollar, so who cares?
Try the panorama mode! Holy crap, amazing! I have never used a panorama app that worked as well as this one, makes me REALLY want these devs to get CM9 working on the revo!
Anyways, nice app, I think it's worth the dollar. Just because it's "only a port" doesn't mean it was simply a matter of getting the APK. I'm sure there were modifications that had to be made to make it work on Android versions older than 4.0.