Various parts of the UI, most notably the account number, are made unusable or at least less nice when iOS’s larger text feature is used. The issue can be seen by enabling Larger Accessibility Sizes in Settings -> General -> Accessibility -> Larger Text and moving the slider to the right. I have mine set to the fourth notch from the right, which causes the behaviour seen in the images I’ve attached. iOS 11 improves Dynamic Type to make supporting it easier, but since I’m using an iPhone 5 at the moment I won’t get iOS 11. I have no idea how many Monzo users are on such old devices, but I imagine there are a few of us.
As can also be seen in the images, some bits of the UI support Dynamic Type, whilst others don’t. It’d be nice to see support for Dynamic Type throughout the entire Monzo UI.
These issues aren’t exclusive to the current account app, but were more noticeable since I couldn’t read my account number. (I simply copied it to another app, but that’s obviously not ideal.)