Add Timed Mini-Sections Specific For Categories

I was about to suggest the same exact thing. The general, timed mini-sections are useful, but category specific ones would be a great help. It would also be more useful if we didn't have to "unlock" timed-mini sections, especially if they are category specific.

That would also be a very helpful feature, especially if you want to work on something other than the skills that Khan Academy suggests for you. It's helpful as a guideline if you're stuck, but the "lock" makes it that you can't access it at all.