In this short video, you'll see students playing Word Abacus, Worcle, and Word Warp X. The latter two are particularly interesting because you can touch words from the word lists to find their definitions and usages--something that the students often do, particularly when they create a word by trying plausible combinations of letters.
Word Warp is interesting because you can challenge other players in real time. In the video, Karli and Monique are challenging Mr. Mitchell.
The other fascinating thing I observed is the extent to which the students interact with each other in the process, and the extent to which the conversations that they have revolve around words, spellings, and meanings. Who said learning can't be fun?