Registration
When the GGC app comes up, it will show the Sign In screen if you have not logged in previously. If this is your very first time using the GGC app, you will not be able to sign in since you have not registered yet.
So, if you have not done so previously, tap on "Register" link to go to the Registration screen:
In the Register Screen, enter your email address, password, and password confirmation. (Your email address will be your UserID.) Tap "Register" to create your account.
A verification email will be sent to your email address. Please check your email and click the link to verify your account. The email will look similar to this:
If you don't see the verification email in your inbox within a minute, then please check your Spam folder. In rare cases, an email provider will mark it as Spam.
Another possibility is that you made a typo when you entered your email address. You can test that by going back to the registration page and re-registering, checking carefully to make sure that you typed your email address correctly.
Once you have registered and verified your email address, you will be able to sign in. The first time you sign in, you will be taken to the Create User Profile screen.