The login and password for the app is the same of which you use to access your website manager. If you're not sure what you're email is to login, you can find this by -:

1) Logging into your website manager on your computer

2) From the left hand menu, select 'Mobile App'

3) Here you'll find your email address to access the mobile app

You can also change your password, or add more user accounts by going to the "Access and passwords" section of your website manager.