To open the login screen, go to 'Settings' (under the side menu opened top left or by swiping from the left side of the screen into the middle) and then click on 'Log in / Register'.
The login via Google+ and Facebook is currently not available. Please create a user account using the radio.net icon.
If you have previously used Google or Facebook to login, please send an e-mail at firstname.lastname@example.org or use the contact form - "Answer not found? Ask a question here" - below this article.