Bubble Word is a small, fun and educational game for Android and iPhone by Donoma Games, Inc. There are quite a few similar games to this, such as Lumosity's Word Bubble game, and many more similar-titled ones.
These games are very educational and fun to play. You have to "unscramble" scrambled words by tapping or clicking on their letters in the correct order. If you guessed the word right, the you usually gain points. In the typical Endless game mode, you play as long as you guess the words without failures, and in the Timed mode you have a set time limit to guess an many words as you can.