Brain Workshop is a free open-source version of the dual n-back brain training exercise.

A recent study published in PNAS, an important scientific journal, shows that a memory task called dual n-back improves working memory (short term memory) and fluid intelligence. These findings are important because fluid intelligence was previously thought to be unchangeable.

Those findings have since been replicated twice with strongly positive results, and two more times in smaller studies with weaker, but still positive, results.

Brain Workshop implements this dual n-back task, and enables you to improve your working memory and fluid intelligence. The dual n-back task involves remembering a sequence of spoken letters and a sequence of positions of a square at the same time, and identifying when a letter or position matches the one that appeared n trials earlier. Brain Workshop can closely replicate the conditions of the original study. In addition, it also includes optional extended game modes such as Triple N-Back and Arithmetic N-Back. It also includes features such as statistics tracking, graphs and easy configurability.

http://brainworkshop.net/