To restore previously purchased expansions, press the cog in the main menu and select the "Restore Purchases" button.

While playing another user's puzzle you can press the yellow triangle with an exclamation mark in the top right corner to report. A valid reason for reporting may be that the puzzle cannot be solved without needing to guess.

Not sure how a puzzle works? While playing a puzzle, press the question mark inside a circle in the top right corner. Then press one of the buttons for explanations how a puzzle works.