Actually I wrote my first n-back test close to two years ago, but for myself. The biggest reason why I wanted to make a web version is because of all these brain games popping up, made by people who don't know what they're talking about. This thing is for real.

I'm also working on subitization test variants, but that's much more familiar.

Since you've trained with n-back (for two years!):

Did it improve your fluid intelligence?

How has it affected you personally?

Haha, back then I wasn't really into database applications and built it just to experience it. That's how I know that 2-back is fairly easy and 3-back isn't, but beyond that I can't answer you (yet).

I gave my dad a 3-back test, on which he did surprisingly well, and he said, "oh, that's easy, all you have to do is concentrate." Indeed, a big portion of it is attention.

I started sketching the data structures and the user interface as soon as I saw it on reddit a few hours ago.

But, I'm pretty glad someone else is already working on it. I have finals this week.