Once you have downloaded and opened the Plays app, you will see the initial login menu:
If you don't have a Plays.tv account yet, you will need to Pick a Username; otherwise you can log in with your Plays.tv Account where it says "Already have an account? SIGN IN".
Registering a Plays.tv Account:
To create a Plays.tv account in the app, you first need to claim your Username. Once you have found a username that you want to use, you need to determine how you login. Either sign up through email, or link it with a social account:
Clicking on one of the social account buttons will bring up a new window that will prompt you for your login information for that account. Don't worry, the login for that social account is through their own service; we do not hold onto that information!
Additionally, you can sign up with just an email address which will also request a password for your new Plays.tv account.
Keep in mind, that if you want to have both a standard Username/Password, and a social login, you can do that. Just after setting up the account, you can go HERE to bind a social account, or HERE to set a password and email (if you made the account through a Social Network)