One piece of feedback: please don't require unique usernames. You already have a unique email address, and it's a pain to have to remember another unique username for another site when the first thing I try isn't available.
you don’t really need to remember your username. Log in with email password and you can see your username from the profile screen. I added usernames as the method for team organizers to invite you to their team. Had I gone with email I’d be collecting the email addresses of people who didn’t sign up for DiscoTask, which I don’t really want to do.
