What to do with the coins you earned?

Even though you've earned them you must pay to access them. Dirt dogs.

The coins are used to buy letters. If you are stuck you can buy a single random letter or a specific letter unlock on the board. Or, if you have unlocked it, the 280 coin boost that reveals a large number of letters on the board in one go.

You seriously are Dirt Dogs as one user put it. My coins cannot be used and I get nothing for playing. I really love playing but it is pointless. Not to mention I had to go through a series of puzzles that had no image for them. Kind of ugly.