Waze as well as being a popular navigation app allows you to mark where you parked the car. And find it afterwards. It's not a tracker device though .

For those of us with Toyotas the MyT Toyota app. also has the facility to mark where you parked your car (but is not a tracker).

Ebay.. Gadget. Add sim card. Wire it up. Or remember to charge it regularly. When you want to use it send a text to your self. It'll show you on the map app.