Desktop shopping app, anyone?

Online groceries shopping is, for me, a laborious process, even with the supermarkets' well engineered sites. I think there could be some benefit in having a desktop application which aims to help simplify groceries shopping, as well as a mobile application, and supporting website for quick access on-the-go.

Some of the main features I'm thinking of are:

• Lookup from barcode scanning
• Supporting in-store (offline) shopping - Being able to print the shopping lists according to the shelf locations in-store (also transferring to a mobile app for the same purpose)
• Rebuy rules - Keeping track of different 'rebuy rules', knowing when certain foods go out-of-data and reminding you to buy them again
• Recipe planning - Import recipes and dissect them to work out what needs to be purchased.

I'd be very interested in hearing any other feature ideas that would make your shopping experience better.