Being a huuuuuuuuge Scrabble nerd (and with the travel version of Scrabble to prove it), I went looking for free Scrabble replacement-type games when I remembered Words With Friends had a free version.
So, the main difference between Words With Friends and Scrabble is that it is essentially Scrabble by mail in that you have to wait for your opponent to take her turn.
But, the game is incredibly fun, if riddled with highly annoying ads. But hey, the app is free, and I shouldn’t look a gift horse in the mouth. If you want to play me, I’m BJWanlund on Words With Friends.