This is a great app for training one's working memory. It is more of a CWM (Complex Working Memory) task since not many people can subitize more than 5 items at a time. This task requires counting and remembering how many triangles, squares, circles or colors appear (look at top of grid for what shape/color you are supposed to count) etc. and then inputing that number from 'n' times ago. Use "step" if the flash option is too fast. And thats my one major criticism, the speed of the flash should be adjustable. Other variables that could be offered would be to change the shape from one trial to the next, i.e. so one isnt always counting squares for an entire session. Other than that, good job to the developer. Its challenging! We need more apps that train CWM as it has shown correlation with IQ.

I had a hard time figuring it out- what the task was, and how it worked. For example, it stops when you make a mistake and requires a new start, where all other nbacks I've tried keep on going for a set number of trials- make a mistake and plow on. It's really fast, too fast, and requires instant counts of objects of up to 9 at once. I can't complete the count in the time allotted, so I'm failing not due to memory but simply never getting the answer in the first place.I'll probably try it again, but I'm off to a bad start and not liking it.