Every hydration app I tried had the same problem: it was just me and a number. Log a glass, watch a bar fill, forget about it by Wednesday.

Hydration apps are built for one person. When I looked for one designed for couples, where you each hit your own goal but play as a team, I couldn't find one. So I built it.

DuoDrop is a mobile-first Progressive Web App (PWA) for couples. Every glass of water either of you logs waters one shared plant . It starts as a seedling in a pot and grows into a blossoming tree. You each keep your own daily goal, but the garden only thrives when you both show up.

An uncut recording: Alex logs on the left, and Sam's plant reacts on the right in real time.

This post covers the engineering behind it: realtime sync with Supabase , why all the game rules live in PostgreSQL , how the procedural plant is generated, and what it takes to get web push notifications working on iOS .

👋 I'm a full-stack engineer who enjoys turning small ideas into polished products.…