Microsoft Solitaire Collection - Play Klondike, Spider, Freecell, Pyramid, and TriPeaks! Plus, Daily Challenges!
WordBrain - Each level is a puzzle, where you are challenged to find a number of specific words!
Churchill Solitaire - The most diabolical version of solitaire ever devised. Played by Sir Winston himself. Available via the AppStore and Google.
Hexic Link - Hexic Link is an Addictive, Puzzle, and Single-player video game developed and published by ThinkCube Inc.
Treys - Like solitaire... but fun!
Board Defenders - Puzzel games based on the chess rules