Lumosity is known for its cognitive activities that give your body's most amazing organ a workout. The app asks you a series of questions that make you think about your answer. In the early parts of the training that I have used, the app doesn't resort to questions with false answers or frustratingly complex scenarios like some brain teasers. It has a nice balance of being challenging, but not impossible to solve.
Lumosity started off as a web-based service and then branched out to mobile, which has been hugely successful for the company. Lumosity has logged 20 million overall downloads, and its updated iPhone version, which launched last month, has been used to play 21.5 million mobile brain games. You can download the Lumosity iPad app and the iPhone app from the iOS App Store. The apps are free, but require a US$79.99 yearly subscription if you want to dive deep into brain training offered by the service.