Latest version of "defense: Evolution" is out on Google Play ( https://play.google.com/store/apps/details?id=com.adsumsoft.defenseevolution ) with a zooming in/out function that should make the game easier on smartphones with smaller screens.
The game is free supported by ads and other games installs. The latter is actually quite interesting and it seems much more profitable than the old fashioned ads. I think I'll write a post on it outlining my experience as soon as also the iOS update gets approved and I get an idea of how it fares over there.
Anyway, basically every time a player installs one of the proposed games, the developer gets paid (often around $1!) so, if you like the game concept and would like to offer a little support, please download and then install some of the other games proposed!