I installed a simple app on my smartphone a few weeks ago, and one that has proven to be immensely helpful: it's called OurGroceries.

And what does it do? It lets you manage shopping lists, which can be shared amongst multiple mobile devices. That means if I think of something I need to buy, I can just grab my phone, type it in, and whoever is doing the shopping this week will end up with it on their own phone as well. Simple, but I've been waiting quite a while for someone to build a workable version of this idea.

The most obvious question: why on earth didn't Ralph's, Wal-Mart, Meijers, or any other grocery retailer make their own? I think there's an unmistakable opportunity here: if you were tracking not only what people bought, but also what they intended to buy, that seems like very valuable information.

For example, if I put Charmin Ultra on my shopping list on June 1st, and on June 3rd, I end up purchasing Cottonelle, wouldn't that information be of pretty good use to the grocery store? Why did I change my purchase decision? Was it because the item was on sale? That would at least let the corporate HQ know which types of products, and which brands, for which I'm either price sensitive or insensitive.

Those loyalty cards from grocery stores must be good for something, though I've yet to see what that is. None of the marketing offers I get seem to be targeted to me based on my past purchases.