We talked about this before when we still had the user-specific sign-in – to show how you stand in that tab.

Now that we are not user-specific anymore, we could instead just show the person who is most in negative red (and maybe how much). If you are a power user with many tabs, you directly know who owes most money and is next up to pay – maybe even you – or who you can use as a bank. ;)

Design-wise, the name could simply be shown on the right, next to the arrow, in red.