UPWORDS - Hasbro's 30+ year worldwide word game is now an app for both iOS and Android users. UPWORDS is dort of Scrabbly except you also can stack letters on top of other letters already on the board (up to 5 high) to change words. That results in a gameboard that remains fresh and susceptible to change throughout most of the game. Lots of strategy. It is also available for play directly via FB.