Monzo's new Aura paid credit card costs £15 a month (£180 a year), pays 1% cashback at supermarkets and 0.5% everywhere else, auto-invested if you want it to be. We go through the fee, the cashback, discuss other benefits like the investing fee waiver, the Apple TV and Google perks, and compare it with other cashback cards on the market. Our take: for £180 a year, it feels thin.