This app, a product of Posit Science, is another one that is backed by studies done with this exact technology. One of these studies, which included six of the auditory exercises featured in BrainHQ, found that 40 hours of training led participants to be better, not only at the exercises they were playing, but also at other memory tests. The gains were equivalent to about 10 years of improvement in memory. This is a major finding because it implies that these types of exercises may help improve overall memory, not just the areas on which they are focused. [free; iOS]