Greek: "sharing in common, fellowship"
Shop smarter, together.
Koinonia enables parallel grocery shopping - multiple people can shop the same list simultaneously, marking items as they find them. Real-time peer-to-peer synchronization means everyone sees updates instantly, making household shopping more efficient.
The Problem: Traditional shopping lists are sequential - one person shops while others wait, or you split the list manually and hope you don't duplicate purchases.
The Solution: Share a single list, shop in parallel across different store sections (or different stores!), and watch items get checked off in real-time as your household/roommates/friends find them.
- 🔄 Real-time P2P Sync - No central server, your data stays on your devices
- 🏃 Parallel Shopping - Multiple people shop simultaneously from the same list
- ✅ Instant Updates - Check off items and everyone sees it immediately
- 📱 Share via Link - Send a deep link to join your list
- 🔌 Offline-First - Works without internet, syncs when reconnected
- 🔒 Privacy-Focused - No tracking, no accounts, no data collection
- 🆓 100% FOSS - Licensed under AGPLv3
- Households splitting up grocery runs between store sections
- Roommates coordinating shopping without overlap
- Couples where one shops while the other remembers items
- Groups buying supplies for events or trips
Built with:
- Yjs - CRDT for conflict-free synchronization
- WebRTC - Direct peer-to-peer connections
- Ionic + Capacitor - Cross-platform mobile framework
- React - UI component architecture
Download freshly baked APKs directly from the Releases pages.
Use the versions tagged with Nightly to try out the latest features. Use the versions tagged with Stable if you're planning to daily drive the app.
Available on F-Droid (coming soon)
I don't have an Apple Developer Account yet :(
Or build from source:
git clone https://github.com/yourusername/koinonia.git
cd koinonia
npm install
npm run build
npx cap sync- Create a list - Generate a unique room ID
- Share the link - Send to anyone you want to shop with
- Shop together - Everyone sees real-time updates
- No coordination needed - Items are automatically marked when found
The magic: CRDT (Conflict-free Replicated Data Types) ensures that concurrent edits (like two people checking off different items simultaneously) merge automatically without conflicts.
Koinonia embodies the FOSS principle of true peer-to-peer collaboration - no intermediaries, no surveillance, just people working together efficiently. Your grocery list shouldn't need a corporation's server.
Contributions welcome! See CONTRIBUTING.md for guidelines.
AGPLv3 - See LICENSE for details.
Koinonia (κοινωνία) - From ancient Greek, meaning "sharing in common" or "fellowship." Used historically to describe communities pooling resources and working together. Perfect for a collaborative shopping app that enables true peer-to-peer sharing.
Made with ❤️ for efficient households everywhere