Somebody is watching you and using your own smartphone to do it.

Have you ever had that feeling that someone was watching you. If you have the mSpy application installed on your smartphone or tablet, they could be.

mSpy is a mobile surveillance application that runs on smartphones and tablets including iPhone, Android, BlackBerry, Symbian, iPad and Galaxy Tab devices.

From the company's disclaimer:

My Spy (mSpy) is designed for monitoring your children, employees or others on a smartphone or mobile device that you own or have proper consent to monitor. You are required to notify users of the device that they are being monitored.

Its maker claims that the app is 100% undetectable by the device user, as a sale rep told The Next Web:

After complete installation the application runs in a stealth mode, so it is undetectable and completely invisible for the target phone’s user.

This is some scary stuff. That's why I still carry one of these.
 

http://nakedsecurity.sophos.com/2013/12/05/mspy-app-lets-someone-remotely-snoop-on-you-through-your-phone-or-tablet/