|name||runs on||version(s) I checked||URL||backing store||allows sharing (1)||Android widget?||notes|
|Grocery IQ||iPad, android||Android app is 2.0.2 build 18877; iPad is version 2.0.3 (Sept 2010)||http://www.groceryiq.com/||Their own site||yes||nice idea, but very unreliable. Never sent "sharing request" email to katie; lists appear different on my Android phone versus the iPad (i.e., it doesn't appear to be syncing properly). Smells vaguely scammy, although I can't articulate why.|
|gootasks||iPad||3.1||http://www.runware.com/?lang=en||Google Tasks||in pro version||annoying ads, and come-on for "pro" version, but seems to work fine.|
|awesomenote||iPhone||4.5||http://bridworks.com/anote/en/main/index.php||Google Tasks||doesn't seem to actually sync with Google. Slick but confusing UI.|
|SSI gTasks||android||0.3.63m (Sept 2010)||http://sites.google.com/site/ssi4and/||Google Tasks||yes||yes||not bad. Free version requires manual action to sync. Very considerately lets me use alternate credentials: so I can have it look at Katie's shopping list.|
|GTasks4Android (Dato)||android||0.5.2 (Sept 2010)||http://sites.google.com/site/gtasks4android/||Google Tasks||no||yes||also good; for some reason I slightly prefer this to SSI gTasks. Same alternate-credientials feature as SSI gTasks. Giant caveat, though: doesn't actually sync in the background (so, e.g., if you edit your list with some other app, the widget won't update until you run the app explicitly)|
|geetasks lite||iPhone||1.19 (Sept 2010)||http://www.geetasks.com/||Google Tasks||no||not great; not bad.|
|Cozi||iPhone, android||?||http://cozi.com||Their own site||no||Unlike many iPhone apps, doesn't display a little number in a red circle to alert you to the presence of new items.|
|ourgroceries||android, iPhone||August 2014||http://ourgroceries.com||Their own site||yes||no, oddly||One of the best of the uses-their-own-backing-store apps.|
Initial setup wasn't hard, but was sorta weird; on each installation, you have to find an obscure setting called "list sharing", and enter an email address into it. The email receives a secret link; when you click the link, that lets that instance of the app use the shared list.
If you upgrade to "Pro" ($5), you can add items by scanning a barcode.
The iPad app seems to sync only when you minimize it and reopen it.
Both Android and iPad apps show ads, alas.
|springpad||iPad, android||Android 4.5.7 (May 2014); iPad 1.1.2||http://springpadit.com||Their own site||yes, but requires collaborators to sign up||yes||Very slick, but I get a bad feeling from it: it's complex, and there are a lot of new terms to learn ("Notebooks", "Springs"). I doubt Katie would be willing to use it. For example: I created a check list, then added it to a Notebook. Later I opened the Notebook and couldn't find the check list.|
No specific support for grocery lists, but they do have generic lists.
They use Google Auth, so I don't have to enter a password to use it.
|shutting down June 2014|
|Dropbox||iPad, android||http://dropbox.com||Their own site||no||much harder to use than the above, since it's not specifically designed to manage or share grocery lists. Still, it works.|
|simplenote||everything||iPhone 4.0.5; iPad 3.0.3; Android 1.2.1 (Oct 2014)||http://simplenote.com/||simplenote||yes||Android client seems nice and simple; auth was particularly easy. However, sync isn't reliable; also, markdown-formatted notes don't render properly on Android|
|mnote||android||1.2 (Sept 2010)||http://android.minuo.net/mnote/||simplenote||no||amateur-hour UI: it rejected my email address because I left a trailing space. Utterly perplexing "iPhone compatibility" checkbox in settings.|
|andronoter||android||0.9.7 (Sept 2010)||http://www.andronoter.com/||simplenote||no||seems fine. Not to be confused with "Andronote", which isn't free.|
|RememberTheMilk||iPhone, android||Android 4.0.17||http://www.rememberthemilk.com/||Their own site||yes||yes||Decent phone apps; decent web UI. Android app seems to work nicely. Praise: http://kk.org/cooltools/remember-the-milk/. (Trivia: years ago, I described the web site as "jaw-slackeningly awful" but it's gotten a lot better.)|
|snaptic aka catch||android||"3 banana" is the name of the android app||https://snaptic.com/||Their own site||?||looks pretty much like every other|
|Todoist||android, ios, web||November 2014||http://todoist.com/||Their own site||yes||yep, pretty nice, too||Very professional. A bit more complex than I'd like, and a few minor glitches when signing up. Sync is nice and fast. No badges on the iOS app, though.|
|Brilliant Intent Notes||android||http://sites.google.com/site/brilliantintentnotes/||?||?||doesn't sync as of 26 Oct 2010, but web site says "coming soon". Most recent entry on the web site is May 16, 2012 (I'm writing this in November 2014). Site's home page misspells "lets" as "let's" three times right up front.|
|note everything||android||market://search?q=de.softxperience.android.noteeverything||Web site (http://softxperience.de/23-0-Note-Everything.html) looks amatuerish; based on that site, the app looks complex.|
|todo.txt||android||https://github.com/ginatrapani/todo.txt-touch/downloads||dropbox||Interesting mostly because the author writes for Lifehacker. http://lifehacker.com/5738007/todotxt-touch-for-android-now-available-to-test|
|taskos to-do list||android||2.13||taskos.com||optionally syncs with gtasks||voice input. UI is good. Syncs with gtasks. Combined my various task lists into one for display, but gave each task a "category" that was the name of the original list -- not bad.|
|A-to-Z notes free||android||1.3||amateurish|
|tasks||android||1.1||https://play.google.com/store/apps/details?id=ch.teamtasks.tasks.paid||Google Tasks||no||yes||Apart from its inability to share, the best task-list thing I've seen.|
|workflowy||browser, android, iOS||2016-11-21 (Android app version 1.6)||http://workflowy.com||their service||dunno||no||Android app with offline access. I think there are also iOS apps too.|
|Evernote||android, iPhone, browser||May 2014||http://evernote.com/evernote/||their service||read-only unless you're a Premium member; dunno if the sharee also needs to be Premium. In any case, the sharee needs their own Evernote account.||lame but yes||Seems to do everything I'd want for a general notetaking app. (I didn't look at it with shopping lists in mind). But. The UI is awkward and nonstandard. I didn't run into any out-and-out bugs, but the nonstandardness (just one example: some popup in the android app had, instead of the standard OK and Cancel buttons, something like "Accept" and "Discard". Why? And the widget was apparently handmade, too; not one of the standard Android ones) makes me distrust the entire app. I also get the feeling that this app is more interested in showing me ads, or scraping my personal information, than it is in helping me.|
|trello||android, browser, ios. Slack, too, whatever that could mean.||2016-11-21||http://trello.com||their service||yes||no||I admit this is pretty far from a shopping-list app, but could probably be coerced into acting like one. On the plus side, the developers are genuinely awesome (it's the Fog Creek guys). Offline sync worked nicely the one time I tried it.|
|wunderlist||everything||Sept 2014||https://www.wunderlist.com/en/||their service, apparently||yes||yes||Surprisingly slick.|
|zbase||iOS||--||http://www.ericsink.com/entries/zbase.html||yes||I know very little about it, but Eric Sink writes well! :-)|
|keep||android, browser, ios||2/1/2016||https://drive.google.com/keep/||yes||yes||Seems to do everything I want. In fact, this is what I actually use.|
|quip||everything||july 2013||http://quip.com||theirs||yes||no||not really usable on Android, but they do consider the Android app a "preview"|
|Plain old Google Docs||everything||May 2014||https://docs.google.com/||Google, duh||yep||some ("drive" and "sheets")||Dunno why I didn't think of this before; it might be all we need. Works offline. And when you're online, and someone else is too, you can see their cursor. On the other hand ... I recently used this on my phone while shopping, and "checking off" items was tricky and tedious. I had my shopping list as a spreadsheet, and "checked off" items by formatting their row with strikethrough; maybe there's a better way to do it.|
|vesper||iOS||May 2014||http://vesperapp.co/||their own, I guess||no||no||beautifully done; the author blogs at http://inessential.com/. OS X and/or web clients might be on the way.|
|Buy Me A Pie||everything||Sept 2017||https://buymeapie.com/||their own, I guess||yes||Haven't actually tried it, but it looks slick|
|(1) by "allows sharing", I mean: I can authenticate as me, but allow katie to view and edit, without her having to use the same credentials I use.|
|http://www.theverge.com/2014/9/19/6397927/best-to-do-list-app has a review of some of these.|