Ruzzle is a very popular game that you can play against your friends. In this game for Android and iOS you get to see a sign of four by four letters within two minutes, you then need to make as many words from these letters by connecting them together in any direction. After three rounds, the game is finished and the one who has collected the most points is the winner. By playing more often, you become adept at finding the words and you will also be able to make increasingly longer words
The free version of this app has the disadvantage that you have to wait five seconds before you can continue after each round, but this is not very disturbing. Until recently, this game was called Rumble but now the name is changed to Ruzzle.