Question about game coins in Android scrabble

I’ve just started playing scrabble on my Samsung phone and I love it. The problem is that there are a lot of ads. I would buy an ad-free game but none is available (only through the apple store). I notice there is a store within the game that lets me buy coins but nowhere does it say what I can do with these coins. I presume it allows for some ad-free play but I’m not sure. Can anyone confirm?

Giving this one more run through.

Moderator Action

Since this is about a game, let’s move it to the Game Room (from GQ).

I find it very odd that this game asks you to buy coins without telling you what you can spend them on.