If you're constantly writing yourself notes to remember to pick up the dry cleaning or return a book borrowed from a friend, those little scribbles are missing one thing -- GPS data. But why does GPS matter? For apps like Checkmark, of course, which will remind you of all the things on your to-do list based on time and location.
What does it do?
Checkmark lets you designate all the places you frequent -- home, work, school, a friend's house, etc -- and set up reminders for the tasks you must accomplish when you arrive or leave those locales.
Why do we like it?
Of course, Apple has had a reminders app that first showed up in iOS 5 and is now integrated into Mountain Lion, but it's not particularly reliable and eats up battery on your device. So this is a good alternative, with an attractive and easy-to-use interface. It's so simple that you just need to tap three times to set up a notification. When you walk by the bottle shop, for example, you won't forget to pick up a bottle of grappa for dinner.
Download this app for: iPhone ($0.99 introductory price) The best: make reminders quickly The worst: similar native app exists