Google play store is the world of application you can download any android application from here exept banned application almost of the application from google play store are free but some of the application you have to purchase it from playstore like grand thef auto and power ramp music player .every anroid phone is compulsury had it without this you cant instal true applications to your phone it provide apps games books movies etc.if software devolpoer devolop his software it provides update and there you can write review if application is good you can give 4-5 star and give suggesions to improve app good one