I've known about this project for a while, but the coronavirus lockdown led me to install it. Unfortunately, the JavaScript-based UPC/EAN barcode scanning is unusable. Too slow, even on a 2018 Mac Pro, sometimes only scans a partial barcode, and asks for permission to access the camera for every scan. I've ordered a USB bar code scanner, I'll see if that makes it more usable.
I used to have a really neat device called the Hiku. It was essentially a WiFi-enabled hockey-puck sized scanner, with a microphone for voice recognition for items without bar codes, and a UPC database. Sadly they went out of business a few years ago but their app still works (not sure if new users can sign up for it), and is great for shared shopping, e.g. yesterday I was shopping and I could see my wife add items to the list in real time, as well as cross them out.
My main challenge is that I downsized to a much smaller apartment, and a lot of our dry groceries have to go in plastic bins that are shoved in dark corners, so it's hard to know what we have or don't have, leading to duplicated purchases and also wasted food when it expires.
One challenge is the absence of a good universal UPC/EAN database. I tried one with one item from the bin (a box of some obscure knock-offs of Meiji Chocorooms), and when the phone scanner finally managed to get the item right, the online DB identified it as a Disney Princess doll, so it seems UPC/EAN is so badly managed they can't even avoid duplicate codes.
Finally data entry of expiration dates is going to be too cumbersome. A better approach would be to have some sort of of statistical model that estimates the shelf life from the product descriptions, e.g. 2 years for canned goods. Less precise, but more manageable, it could show alerts like "check how much longer this can of tuna has left", and if still has some ways, you could enter the precise date only then.