Mobile games without ads! Fun and non-intrusive.
A free and open-source clone of Civilizations 5 with all the strategic, empire-building depth but minus the visual flare, Unciv provides a challenging experience with no bloat, no ads, no privacy concerns. It's available across desktop platforms and Android devices.
The encompassing chess experience, Lichess offers accessible but powerful tools for multi-platform gaming, practice, learning and even just watching. From the graphics and intuitive UI to its endless supply of players from a global community, this platform gets everything right. And it's all available totally free, with no ads.
Beautiful, isometric visuals with crafty puzzles bundled with a super intuitive interface that anyone can jump into. Mekorama is the donation-based puzzler that lets you play without obtrusive ads and pay only what you think it's worth.
Possibly the best dungeon crawling game around, Unleashed Pixel Dungeon is a slightly easier variant of the popular and similarly open-source 
Pixel Dungeon. It's a perfect coffee-table game with just the right blend of retro visuals and mobile-centered control. And for those looking for a much tougher experience, there's always its hardcore sibling 
Shattered Pixel Dungeon.
A merger of factory sim and tower defense, Mindustry successfully ties the two together in an enjoyable single and multi-player game. The whole experience is ad-free and the game can be played totally free on Android and desktop systems via downloads from the official site. Meanwhile, the full game is available at a very low cost on iOS and via Steam.
Patience Revisited has a large selection of classic and new solitaire games, all for free with no ads and tons of customization features.
A mobile throwback to the classic PC-based, real-time strategy games, Warfare Incorporated has the retro feel of those originals but with its own style and advanced but manageable units and progression.
A practically endless variety of puzzles is provided through popular sources and downloads are automated players can just select a source and start playing a new puzzle in moments.
A free and open source pinball game, with simple vector graphics, a physics library for accurate simulation, two table layouts, and no ads. Runs best on fast devices, adjusts frame rate as needed on slower devices.
Valve, the company behind Steam, has blessed the world of gamers with a free but enthralling chess-based strategy game that's available across multiple platforms without any ad bloat.
