It's free with minimal IAP
After a recommendation from a colleague yesterday, I stumbled across Ookibloks -- an unassuming puzzle game starring a cute monkey. Five hours later I was in a haze of blocks and bananas, completely unaware of where my afternoon went. The premise is relatively simple -- crabs have stolen the main character's banana stash (Donkey Kong Country style), so you'll help him get it back by way of swipe controls.
Each puzzle arena is filled with blocks -- some of them are hazards, some have enemies hovering around them, and others are bananas, which you'll want to fling into to capture. You can't capture a block while you're standing right next to it, so you'll have to fling around by swiping your device until you can slam into it.
It's a free add-supported game, but the purchase of any IAPs (including the $0.99 option) remove them entirely. There are other IAPs designed as power-ups, but they're completely unnecessary to finish the game, and you can earn them anyway through a cute capsule toy minigame.
If you're looking for a fun little puzzler to spend the weekend with, check out Ookibloks.