Deezer-how does it work and how much does it cost?

I have downloaded the deezer app to my iphone. I just don't understand how it works and how much it cost after the free 15 day trial

Deezer will cost £10 a month, you wont be charged because you havent entered any card details. Deezer is a music streaming service like spotify. This means that you basically listen to music through the internet ( full quality sound). You can create a playlist and listen to it offline which means you can listen to the music if you dont have an internet connection on your phone. Its a good app i have it aswell. So basically its legal and you dont have to buy music which is about £0, 99p a song:)