How can I find out who is spying on me? I have a Samsung Galaxy S4.
You can't find out who is spying on you, but you can use Anti Spy Mobile Free to detect and remove all spyware applications from your cell phone. Usually, these applications can monitor your calls, SMS messages, and even your location and are installed by someone who has access to your device.
First, you need to check whether you have a spy software on your phone, then you should think out who have access to it and also can install spy app on it. By the way, some software like Mobile Spy is undetectable and will not be found by antivirus.
1st thing I'd do is search sys internals. If you were hacked, you'd see a total changeover with-in op.sys. Just open the file and quarantine/sandbox the item. the rest is up to you.
To be honest, it is a little difficult to check if anyone is spying on you! As far as I know, phone spy app like iKeyMonitor can invisibly run to record everything, and send logs to appointed email automatically, so it's hard to find out it.