Parkbud

If you're in the habit of forgetting where you've parked your car, or how long you've got left on the meter, Parkbud could be your saving grace. If you're not, you probably won't find much use for it. When you've parked up, place a marker on its map, tell it how long you've paid for and how long in advance of that you'd like it to nudge you, and leave it to its business. It'll even guide you back to your car.