Public restroom finders exist but don't indicate cleanliness, wait times, or accessibility features.
Build a mobile app where users can rate restrooms on key factors and report maintenance issues. Include filters for specific needs like baby changing or disability access.
Monetize through sponsored locations and premium features for frequent travelers. Partner with municipalities and businesses to keep data fresh.
MVP could start with importing existing location data plus simple up/down voting. Biggest challenge is getting critical mass of users.