I have been using the tadalist.com web site and have been generally happy with it. It's a web page that works in any browser, so it's really easy to sync with; my wife can add the half-dozen items she forgot to put on the initial list while I'm on the way to the store and I'll see them when I get there.
The problem is that I only have marginal connectivity at best in the stores where I do most of my shopping, and often it drops to zero bars. With the previous version of the tadalist.com software, that was only a relatively minor inconvenience: each item had a checkbox, and even when I was offline the checkbox worked (although moving a checked item to the bottom of the list only happened when I was in a part of the store where I had a signal). However, they just changed how the list works on my phone, and there's no more checkbox: the only way to identify that an item has been bought is when it moves to the bottom of the list and is shown with a strikethrough, and you can only make that happen when you're connected to their server.
So what I'm looking for is an application that has good synchronization via a server like tadalist.com but is also functional when I'm in a dead zone in the store (i.e., shows me what I've bought and updates the server once connectivity is restored). Do either of these fill that bill, or are there others I should consider? I really don't care about recipes and master lists and stuff like that; I just want a list that syncs well but works locally when I'm offline.
Thanks for any suggestions.