How progressive difficulty works

PlugBrain has dozens of math challenges, sorted from easy to hard.

They start with adding numbers under five and go all the way to multiplying big numbers.

You choose two things when you set it up. How often your apps get locked, and the easiest level you want to see.

Then the app takes over.

Each time you solve a challenge, the next one moves up a level. Open your apps again and again, and the sums keep growing.

Stay away, and it goes the other way. For every two lock periods without a challenge, the difficulty drops one level.

It never drops below the level you chose.

So a quick check stays quick. A long scroll gets slower and slower to get back to.

There is no streak to keep and no score to lose. Just a challenge that follows what you actually do.