Specifically 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