What is it? Take a gander over on their website and you will see, the focus is on providing a tool for users that will make it easier to organize and remember things. Such as… ‘honey, don’t forget the milk at the store’. :)
And they are doing a great job meeting a need. For me, and I suspect for many others.
If you haven’t used it, you should check it out. They offer a number of useful features with some easy and intuitive interactions. While I can see areas they could improve (Setting task locations that don’t yet exist on your map), they generally get it right in terms of a usable site with clear utility.
Good job guys!