Direct link to user registration: press here
Otherwise: To signup, you have a few options. First, on the upper right corner of the screen, press the menu-button, and after that, "log in".
Now you can choose to sign in with Facebook or Google+.
To create your own separate account, click "Create an account".
- Fill in the blanks on the "User Registration" page.
- You're good to go!
See this video for more details: