The theory is that you sign up (within the app), and come close to game time you'll be able to see any available upgrades (and how much they cost). It's meant to be location-sensitive (and offer you upgrades nearby). I don't know if they just didn't bother with the RDS being not very big, or if the location part didn't work. I was offered seats in either end of Anglesea and Grand stands.
"You'd better watch who you're calling a child, Lois. Because if I'm a child, you know what that makes you? A paedophile. And I'll be damned if I'm gonna be lectured by a pervert"