A free program for Android, by SimFun.

Memory Test: Memory Training Games, Brain Training is a memory game with puzzles, where you will be presented with a list of images. You have to match the images, and you will be given a score based on how quickly you can do it. If you get the exact right answer, you will get a bonus.

The game is a simple one. You just need to tap the screen to view the next image, and you need to tap the screen to view the previous image. You need to keep answering until the time runs out. Each level has a time limit, so you need to get to the next level as soon as possible.