Just log in, enter your race and age, then indicate your gender on the sliding scale between male and female, and bam! An equitable, not equal, division of the bill.
If you're given a higher amount than you want to pay, you can protest and indicate and excuse from their list, including "this isn't an issue anymore" or "just spent $400 on improv classes." The app won't give you any sympathy though.
Of course there are issues with this in general - I feel fairly certain I am under-earning for my demographic, for example. Consider it more of an educational tool: if everyone was paying based on what they got the opportunity to earn, how would things be split?