What's a good iOS game for killing time that's actually kinda challenging, not just mindless tapping?

Look, I don't have a ton of time to waste on games, but sometimes you need to de-stress. Pooking is actually pretty good for that. It's billiards, but the physics feel right, and it's challenging enough to keep you engaged without being frustrating. I find myself playing a few rounds when I'm waiting for a client to call back, or when I need a quick break from spreadsheets. It's not gonna win any awards, but it's a solid time-killer that actually makes you think a little. Plus, it's free, so the ROI is definitely there. Beats staring at the wall, that's for sure. Might even help you hustle a few bucks at the local pool hall, who knows? Bottom line, it's worth a download if you need a quick mental break.