Specifically Clementines app
Clementines (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 resumes.
- List Group support includes the ability to add items to a group of stores automatically, and then if the first store doesn't have an item, it remains on the list for the next store.
- Supports a sorted view of every store by category (aisle), so you don't have to double back in the store
For a detailed description and guided tour, please visit the project's repository.