Turn based fantasy games have seen a bit of a resurgence recently, no doubt partly because it's easier to design a touchscreen UI where the action takes place in a menu rather than in wielding a sword. To wit: King's Bounty: Legions. This title gives players a set of characters to command in combat versus an enemy squad to conquer the game board.
The game has some pretty strong creative ties to Heroes of Might and Magic, as the man who designed the original Might and Magic, as well as the aforementioned spin-off, also worked on the first King's Bounty. This new title has some pretty great looking graphics behind it, as well as the ability to challenge players from around the world. Users can log in as a guest, though if you use your Facebook account, your progress will be saved between your Android device, an iPad (if you have one) and Facebook itself.
King's Bounty: Legions is free to play, though it seems that right now it's limited strictly to Tegra tablets. I was able to install it on my Nexus 7 just fine, but neither the Galaxy Nexus nor Nexus 10 were eligible. No explicit restriction is made in the app's description that requires a tablet, though judging from the UI, it's unlikely any phone would be big enough (touch targets were even difficult to hit on my N7).
Of course, in-app-purchases are present as well. You can use real money to buy in-game money to acquire better items, weapons, or characters. Naturally these are optional, but it's likely the game will tempt you to skip grinding by doling out a bit of cash.