4 Pics 1 Word app review

It's a quiz. On each step you see 4 pictures which are connected by one word and your task is to write this word using 12 letters proposed for this task lower. One by one the associative array becomes more sophisticated and you need to think over to find the right word for 4 pictures. The app is free but when you are stuck with some level you can buy coins which can be used to write the correct word or to eliminate some letters from possible list. This app is nice but I got in a situation when I can not guess the correct word and the only thing I can do to keep playing is pay $0.99 for 350 coins. I am not really excited by this app so I prefer to close it. The app is nice but nothing more. I got through 15 levels before the problems started.