This app was mentioned in 5 comments, with an average of 1.20 upvotes
I like Buy me a Pie because you and your friend/partner/whatever can access the list. If you are at home you can just add items and it appears in their list as they are out shopping.
Yet another option is "Buy Me a Pie!" - https://play.google.com/store/apps/details?id=com.buymeapie.bmap
It is very simple, just like you wanted. But does offer some usable features compared to "generic checklists" like Google Keep. For example, the items are automatically grouped by category. So you don't have to go back and forth between the same aisles.
I use Buy me a Pie! and/or Google Keep.