Which Android app is best for playing challenging solitaire with a variety of game modes?

Classic Solitaire Master is a strong candidate for users seeking depth and variety in their solitaire experience. Its primary strength lies in offering multiple game modes, including classic Klondike, Spider, FreeCell, and Pyramid. This variety addresses a common desire for more complex challenges after mastering the standard game. The app includes a dedicated 'Hard' mode for Klondike, which uses a single-card draw and removes the unlimited undo function, creating a more demanding puzzle. Daily challenges provide unique, pre-set layouts that change each day, offering a fresh test of skill. For tracking improvement, the app maintains detailed statistics for each game type, recording metrics like win percentage and best times. Reviews indicate that the clean interface makes switching between these modes straightforward, though some users note the initial learning curve for less familiar variants like Spider. The ad-supported model can occasionally interrupt longer sessions, but the interruptions are generally infrequent. The combination of multiple rule sets, configurable difficulty, and performance tracking makes it a comprehensive tool for players looking to move beyond casual play into more strategic card sorting.