Hi Neven, great start. You had a good idea, and acted on it. We should all be so motivated. I'd like to suggest an alternative to your list above.
Backstory: My father's a retired accountant, so he's meticulous--some would say obsessive--about lists. When I was young he typed up a list of all the items he ever got at the supermarket, with a box in front of each so he could check the ones he needed that week (in those days you typed left-bracket right-bracket like this [] to make a box). He organized them by categories, and then further by the sequence in which those categories appeared on the shelves as he walked through his supermarket! The list fit on one page. He made a bunch of copies of his list, and used one per week. Items could be checked over several days, as the need for them was noted, and when it was time to go to the store the list was ready and tailored for an efficient food-shopping experience.
The list served particularly well when my mom was hospitalized for a year and dad had to run a household, care for an infant daughter, and keep his job.
So what's to learn from him?
1. Shopping lists are personal.
Some posters have noted their desire for a more vegetarian orientation, for example. Others will want to remind themselves of the brand or size of a product they prefer to get. My dad's list was his list. Your type-in function allows that personalization: the question is how it's best utilized.
2. Shopping lists need to be comprehensive.
It's four decades since my dad typed his list, but I think your project could best serve users if it emulated his approach, to develop a personalized list of all the items the user ever purchases at the grocery. Using the app then requires the user to simply access it at any time during the week, click on items as the need for them is noted (no new entry necessary) and then make a final sweep of the pantry and frig before leaving for the store. Note that with this procedure even if you're out and have failed to make that final check, but find yourself driving past the grocery and remembering you need milk, you'll have a reasonably current list with you and won't end up at home afterwards thinking, "s**t, i needed toilet paper, too." And if you're in the store and try something new, you can add it to your iPhone OneTrip list on the spot.
3. It's the first column of OneTrip that counts.
The end product is the shopping list and that's where the emphasis should be. I see two ways OneTrip could achieve that. The first is if the comprehensive, personalized list is built during set-up to be the first column, and thereafter the user simply scans down it to see what's checked, and thus needed. Alternately, as the user selects items in a comprehensive list in column two, those items move to create the week's contents of column one. In this case, everything in column one is a needed item, rather than only those items that have been checked. I prefer this latter approach: as the week proceeds, column one grows, and is your shopping list. But column two remains your pool of possibilities.
4. Categories may need to be re-thought.
They could be expanded greatly to suggest many more possibilities for first-time users during setup. They could be imposed on the "comprehensive" list I'm proposing, so that it doesn't become unwieldy. Better yet, perhaps there's a way to weight the elements of the list so that those that are selected most frequently (or always?) move not just to the top of the list, but to a special category on the comlprehensive list, similar to the Finder's "recent folders" category. A user could quickly scan the contents of that category and choose a "select all" button, or un-check just a few that aren't needed at the moment and then select the category, quickly moving onto the final list a large number of staples with minimal input.
My dad's 86 now. He gave up his computer last year when he was exhausted by the spam and viruses choking his Windows machine (I know, we should have gotten him a mac, and that's a different story). But your OneTrip app (applet?) would impress him as a way computers could improve on the methods he developed decades ago. Imagine: in those pre-word processor days, he had to retype the whole list just to add an item in its appropriate section. Now, editing's immediate, and the list is always at hand. A better shopping list! Like the proverbial better moustrap, that is progress. Well done.
peace
terry
