Bombardiers Guild might count - it has turrets and projectiles! Not sure if the OP is asking for a "tank-like game" (genre) or a "game with tanks" (content)....
Pocket tanks is the best! But one new one that is actually pretty good (and ignored) is Galactic Tanks! Its not half bad for 99 cents and the dev made an update in like three days
This one does look pretty darned good, I would have picked it up if I wasn't in the middle of Bombardiers Guild and Star Hogs (and Kill.A.Ton and... how many tank games do I have on here, anyway... *runs off to count*)
lol yeah too many tanks games! Bombardiers guild is pretty dang good, more of an artillary game right?
Yes. Artillery with planet affected gravity. Two guns at each end of the screen, with planets in the middle to shoot around. Very well polished game, multiplayer is way too cool. It's not the buck, it's the time to play all these great games!
T.A.N.K. Arena Battle These were featured in App Store There is a forum for T.A.N.K. right here (YouTube video and screen shots) http://forums.toucharcade.com/showthread.php?t=12110&highlight=tank+arena+battle Or you can check it out in App Store http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=315266776&mt=8