Quantified Mind (free alternative to Lumosity)

"If you could measure how your mental performance varies day-to-day and year-to-year, what would you do? Try to make yourself smarter? Improve your focus and energy? Fight cognitive decline?

Quantified Mind is a tool that quickly, reliably, and comprehensively measures your basic cognitive abilities. We've adapted tests used by psychologists to a practical web application that you can use whenever, wherever, and as often as you want....

We are scientifically quantifying the effects of interventions on our cognitive processes. If something will make you smarter, we want to know! Eating butter, taking creatine, meditating -- who knows what really works? To see whether something improves cognition, you need to try things and measure the results. With enough data, the effects are clear."

Check out Quantified Mind