Improve shared tabs: Split the remainder evenly when editing someone's amount

[awjdean]

This feature has already been suggested. You can vote for it here:

Bill Splits: improve how custom amounts are allocated

A niggle for me when I’m splitting the bill is that I can’t type a custom amount in for myself, only for others in the group. If I’m splitting with one other person for example - I know how much I’m paying and want them to pay the remainder. But I have to calculate that remainder manually and type it into their box - because I can’t type my share into my box.