When you signed up for an app account we sent you an email with a verification link. Click this link to verify that the email address belongs to you. You will see a web page confirming that you are verified. When you return to the app you can continue using the app as a verified user.
If you didn't get the email; please check your spam folder or any other filter you may have on your email client. Please also double check that you entered the email correctly, the app will show which email address we sent the verification link to. The email should normally arrive quickly, but in rare cases if you still didn't get it after more than 15 minutes, please let us know and we'll resend it.