WordBubbles! comes from Apprope and is very popular. The object is to find words, use up all the letters and then move on. The concept borrows from Boggle. (I once heard a story about 2 sisters who, whenever they get together, have a marathon Boggle competition.)
WordBubbles! has a lot going for it. Unfortunately, they have a lot of ads.
Very Interesting: I was stuck on a 6 letter word. I showed it to 4 others. They couldn't get it. The next day, that puzzle was replaced with another. It appears that Apprope wants to keep me going at all costs, hoping that I'll maybe buy some hints.