Tokens are used to unlock new puzzles from the Map View screen.

On this screen you will see a grid of yellow sticky labels. Each of these labels represents a puzzle in the current chapter, and shows the number of tokens that must be spent to unlock and play that puzzle.

When you unlock a puzzle, it will remain unlocked until you have completed it, and will appear on the Map View as a pink label. Once you have completed a puzzle, its label will be removed from the Map View, revealing part of the chapter's photo beneath.

Once you have completed all the puzzles in a chapter, you can return to it to replay any of the puzzles for free.

The number of tokens you have available is listed in the status bar at the bottom of the screen.