CourtSide is a badminton club app. Live scoring, session attendance, and player stats. The problem it solves is narrow: club nights are run on paper or a group chat. Nobody knows who's played whom, matchups get lopsided, and the score resets every time a phone locks. What it does: Full BWF rules engine — 21 / win by 2 / cap 30, doubles service rotation, singles side-switching. Not a tap counter. Session planner: check players in, auto-generate fair doubles rounds, finish the session for a leaderboard summary. Club and player stats — win %, form, best partner. Offline-first. The scoring engine is event-sourced and local; it pushes to the cloud when you reconnect. Web (guest mode — quick match + spectating): https://courtside-links.vercel.app Android: https://play.google.com/store/apps/d