I'm looking for recommendations for an application that would allow me and my wife who both Android phones to track our 16 years old sons iphone. He's now driving and we ask him to check in and let us know when he arrives to where he's going and most often he forgets or doesn't bother to let us know. Ideally I'd like something he won't be able to turn off or disable. Anyone using an application free or paid that they like and would recommend? Thanks