Android: Whether you parked on a side street or in a huge parking lot, it's not always easy to find your car at the end of the day. Valet is an elegant app that gets you back to your vehicle without any confusion.
Once you park, fire up Valet and click "Park My Car", and the app will drop a pin on your current location. From here, you can set a timer to warn you if your meter is running low. When you're ready to get back to your vehicle, the app will also show you turn by turn walking directions to help you out.
These features by themselves make for a decent app, but Valet has a secret up its sleeve that makes it worth the $2 price tag. If your car has a Bluetooth audio system, pair it to your phone, and enable Auto Parking in the Valet settings menu. Now the app will monitor when you leave your car by detecting when the phone loses its Bluetooth connection, and automatically mark it as parked in the background. If you own an Android phone and car with Bluetooth, there's no good reason not to download this app.