The latest beta version of Google Maps for Android includes a parking reminder feature that'll help you figure out where you parked. Users can tap a blue dot to save their location. The dot pulls up options for entering notes and saving photos of your parking space.
You can also enter how much time you have left on your spot, allowing Google Maps to help you not go over your allotted time.
Google has not said when the public version of Maps or the iOS version will receive parking reminders.