I am sure every teacher has played Scrabble with students at some point. But, it's not the easiest game to come across. Sometimes a school or another teacher will own it, but not always.
Babble is perfect for if you don't have access to actual Scrabble. Babble is just like Scrabble, except there is no board. Students can make words in any direction but they don't need to stick to the board. This does, of course, mean there are no triple or double word/letter scores, this should make it simpler to play and work out the scores.
All you have to do is print it out, cut out the letter tiles (this may take some time, sorry) and cut and fold the letter holders. Then you are ready to play with your students. Don't forget, you can always split your class into teams and have them play together.