How can I get a hint if I'm stuck on a puzzle?

To the bottom right of the number grid you should see two buttons marked with a STAR and a QUESTION MARK. These allow you to spend coins or ...

How do I turn off the Playing Tips (the hints that pop-up when the game is left idle for a few moments)?

The Playing Tips can be turned off through the Pause Menu.Tap the pause button at the top right of the screen, select ‘Settings’ and select ...