We just released a free turn-based strategy game for Android called War Puzzle:Navy.
It's a fast, easy to play "beer and pretzels" style single player game.
It has 25 levels and the max time to play a level is about 15 minutes,
It's ad free and there are no in game purchases.
Please give it a try, we welcome feedback.
Thanks. https://play.google.com/store/apps/details?id=com.hotmail.gmplayer.War_Puzzle