On-line grocery shopping is a fantastic service but we still create mental lists of the things we need as they occur to us while we go about our business. These items need to be recalled when we're ready to sit down and create an order - even those who create written lists still need to transcribe them. Those of you who log-on repeatedly to add items a few at a time need not worry (but who has the time or inclination for that?).
So for those of us who only remember that we were meant to have bought something when we are faced with a bare spot in the pantry, a simple shopping list app for smartphones could save time and frustration.
You could configure the app to integrate with your online grocer(s) of choice by providing log-in details for you accounts once you've installed the app. You could then whip out your phone and identify anything you'd like added to your next order at any time and a message identifying the item and the required quantity would be sent with your account details to the grocer's site. The next time you log-on to place an order, hey presto the ad hoc items you've added are already waiting for you - of course you can still cancel or amend as usual.
Identifying items should be fairly simple by using fairly common methods. Firstly, manual entry on the key-pad/touchscreen, with a history for recalling previous and common items; this could be linked to the grocer via data services for an exact match (if not available, a matching facility for submitted items could be made available on the grocer's site). Secondly, barcode scanning using standard APIs; again this would give an exact match to the grocer's stock.
Thirdly, and perhaps the technology isn't quite perfect yet, voice recognition - you say what you want and it goes and looks for a match for you to confirm. Finally, and also a technology that's not quite ready yet, camera based recognition (as used by Google shopper) - this would use the camera to recognise brands, packaging or common food types (eggs, tomatoes etc).
I think with a combination of these technologies this app is perfectly feasible and could add another time saving multi-tasking tool for life in real-time. The app could also be used collaboratively, every member of a family would be able to add to the household shopping list or members of staff in an office could add requests to a periodic stationery order.