For my money, the best civ-type game out right now is Super Tribes. I know it's out for IOS and I think there's an Android version too. It's free, and it's really, really good. Great graphics and sound, rock solid programming (never hit a crash or bug), and really clever design. And when I say "free" I mean really free. There are extra tribes you can buy as IAP, but you can play the whole game without paying a cent and there are no timers or other pay-to-win crap like *ahem* certain other games I can think of.