I have been using this for a long time, and I find it invaluable, now I can control what apps can talk to the net, and i know which are spying on me.
I also use it on my laptop, when going online with my cellphone, I have it so every attempt to access the internet gets displayed, so I do not incur any unnecessary bandwidth charges
Little Snitch
Informs you when an app tries to establish an outgoing Internet connection.
Version: 2.2