This app was mentioned in 7 comments, with an average of 3.14 upvotes
Here's some of my favorites that don't get that much attention:
Rapture is a mix of a God game and an action Risk kind of game. You send out armies, and upgrade your civilisation either by concentrating on tech, economy or religion (which gives you "mana"). You can switch this around as you play based on your options.
The IAP are mostly useless except for the one IAP that gives you access to all spells.
Neo Scavenger is often overlooked for it's graphics and a tad bit smaller UI (it's a PC port). It's an incredible turn based survival game with some crazy detailed text descriptions. It really makes for an intense experience. There's a single IAP to unlock save game.
Party Hard Go is a friggin awesome pixelated game. You play as a murderer and try to kill everyone at a party. It's just so satisfying!
Then there's card games. I know Card Thief is sometimes mentioned, but I've yet to see someone mention Card Crawl, wnich is from the same dev. Basically a card dungeon crawler. Pretty darn cool. Also Miracle Merchant is pretty cool and relaxing too.
Anyway, then there's Onirim. Everyone who loves single player card games should look into this. It's very unique and has it's own set of cards and rules. It's truly one of a kind.