Groceries is an open source and self hosted grocery shopping app, with support for web/mobile and Android / iOS.


Features:

Supports multiple shopping lists and ability to group lists into a list group
Lists can be shared with other users
Updates across multiple platforms and users occur in real-time, synced immediately. Conflict resolution occurs automatically and can be viewed.
Works offline as well, when you don't have internet connectivity. Updates are synced as soon as connectivity resume