I was quite surprised to find out that there was apparently no easy or straight forward way in the Android app to copy the IBAN to clipboard or even forward that one to an instant messenger.

There's a fairly visible "Share" functionality in Fidor Bank's and Ferratum Bank Malta's app. Even KBC Ireland's app (which is really primitive and barebone) does this. I can just press the account number which acts as a "share account number" button and offers me a selection of apps that it can pass the details to.