Lumosity promises to exercise your brain (pictures)
Brain training app Lumosity says it can help beef up brain power.

Lumosity brain training
The Lumosity program is designed to train your brain, and improve your memory, attention, and problem-solving skills. The app is free for iOS and Android, but you need a paid subscription to get the most out of it.
Training workouts
Every day, the app gives you a new training workout. You get three games with a free subscription, and six games if you pay for full access, which costs $12 per month.
Brain games
Each game is designed to exercise a different cognitive skill. Above are two games that help you speed up your decision-making processes. Every game has a tutorial to help you learn how to play.
Brush up on your math skills
One of the games, called Chalkboard Challenge (above), tests your basic math skills with simple addition and subtraction equations.
Full-screen games
The games Lost in Migration (left) and Ebb and Flow (right) are designed to hone your attention and flexibility skills.
Track your progress
When you finish each game, you'll see how many points you earned and how that compares with past sessions.
Daily training
Lumosity recommends you train three to five days per week, but you can easily do it every day.
Lumosity Performance Index
The app measures your progress with the Lumosity Performance Index, a measurement of your game scores in specific cognitive skill areas, such as Attention or Memory. If you have a paid Lumosity subscription, you can compare your LPI with the entire Lumosity community.