Developing a stealth Android app

For my schoolproject I have to develop an Android app that continuously tracks the owner of the phone and let him track the phone when lost.

For this kind of app I need to start the app in the background whenever the phone boot开发者_开发问答s. I was wondering how I could do that?

And perhaps you have some ideas of all the sensors I could use to track if the owner is near the phone.

Thanks!

Use BroadcastReceiver to start somthing on the boot completed.