Word Bubbles is a Flash game that's somewhat similar to Amazon's Every Word for the Kindle.

You get three initial letters ("tru" in the screenshot above), and you need to compose as many English words as possible with those three letters. When you create a six-letter word, the bubble that says "6" rises closer to the surface. When you find another six-letter word, it rises some more. When you've found enough, it will rise all the way out of the water and "burst" into a star.

You don't have all the time in the world to complete each level either; you only get 60 seconds. After that, you simply move on to the next level. That's a big difference compared to Amazon's version. Every Word doesn't limit you in time, but you must find the longest word possible in order to move to the next level.