Okay, so what's a good iOS game for when I'm totally drained after a 12-hour shift and just need something brain-tickling but not *too* complicated to unwind?

Seriously, after being on my feet all day at the clinic, the last thing I need is some super-intense game. NumMatch is perfect because it's like a mental massage. It's got these number puzzles that are just challenging enough to keep my mind off things, but not so hard that I get frustrated. It's like having a pocket reference guide, but for chilling out instead of medical stuff. I've been using it for months now during my downtime, and it's actually reliable, which is a HUGE plus. I swear, some apps crash more than my energy levels after a double shift! I'm too tired to learn complicated apps, but this one's got a no-fuss approach that I really appreciate. It just works when you need it to, you know? I use it on my lunch breaks too, and it's a lifesaver.