A friend of mine recommended the book Game changers by Dave Asprey
(Not to be mistaken with the awesome Netflix documentary).
I haven’t gotten so far in the book. But at the beginning of the book, Dave mentioned Dual n-back exercise as a “permanent RAM upgrade for your brain”.
“There’s one downside, though. The Dual N-Back test is so irritating that it makes you want to throw your computer across the room. Think of it as CrossFit for your brain—you just have to keep pushing.”
Dave Asprey
It seemed like a no-brainer to try it, so I searched google play for it and installed the first hit I found.

I like the sound of that! 🙂
The first test was somewhat easy but started to struggle on the second batch, where I had to remember two steps back.
hard to explain, so you should try it instead 🙂
Dual n-back on Google play