What iWant is an app to keep track of the things you want and need. It’s designed to be a shopping list that you add things to when you think of them. You can add the name, where to get it from, price, category, priority, etc.
Then when you are at a particular store you can filter the list to show items in the list that you can get from that store. So now you will never leave the hardware store without the one thing you in went there for.
You can even set categories, ie “Gardening”. You can then filter the list to show all items from the hardware store in the gardening section that you want.