Not working iPhone 6. Security? – Guitar Lessons: Rock Prodigy Review

Ap not working on iPhone 6. Facebook signin didn't work so forced to use gmail to signup. Everything is blank after sign in w Google. Also recieved an email from google saying there was unauthorized use of my email. I haven't signed up for anything new or used my gmail for anything in a long time other than this ap.
Review by Aggie123456789 on Guitar Lessons: Rock Prodigy.