Rulebook.io is an alternative to Googling "[insert game name] rules pdf"... it's a lightweight, easy-to-use board-game rules viewer.
It's also open-source! Both the website code (https://github.com/camden/rulebook-source) and the rulebooks themselves (https://github.com/camden/rulebooks) are publicly editable.
Hexium is a casual mobile game available now for iOS and Android.
Drag and drop groups of hexes onto the game board. Connect edges with lines of 3 or more hexes in a row and they disappear while you score points! Each level has a goal - some levels you just need to score points while others have slime, ice or bombs that get in your way.