Chances are those apps were hoovering up all the data and then used for personalized advertising. The users are literally telling you what they need to buy. It doesn't get better than that.

So much of what gets invented today is just gimmicky shit which has no earthly use except to make you consume more.

I think the only tricky situation is if there's multiple people to coordinate, who want to add items while not at home, or go shopping on their way home. Other than that any simple (paper) note will do?!

I got an office whiteboard for the kitchen. I write down stuff that's about to run out, or whatever I want to eat in the next days. And once I go shopping, I either memorize the items or snap a picture. No further software needed.

I just use a basic Todo app for my shopping list, but I really like having it on my phone for two reasons:

I can reorder things before I go to match the aisles order. All the HBA together, all the cleaning stuff, all the paper stuff, then swoop across the aisles back to front, dairy, chips, cereal, coffee, cold stuff, canned goods, Mexican, pasta, condiments, freezer, deli/vegetables.

Two, I can check stuff off and it removes it reducing clutter.

Sometimes I use a paper list and I get lost on it and end up backtracking.