Why do I have to pay for an update each year

I like this game and this app works for me. But I honestly do not understand why I have to buy it each year!!!! And app keeps crashing on my iPhone 6 plus I want a refund!!!!

This is an update on my review and things just get worse. I am unable to pick team since the last update. I really wish i could upload a screenshot or give it no star at all.

Nana Kory about Fantasy Premier League 2015/16 - Official App