App to restrict internet to whitelisted apps

Hi

I'm reasonably new to Mac, well, I've been using it since about November last year (Macbook Pro).

I am wondering if there is some sort of app, maybe a type of firewall that will let me restrict internet access to ALL apps except ones which I specifically allow to use it, and have a way to easily enable and disable these restrictions.

The reason for this is that I use my mobile phone for internet access from time to time when I am out on the road, and as you can imagine, data can become quite expensive so I would like to stop all un-necessary traffic when I am using mobile internet.

So something where I can switch from all apps having access, to only whitelisted apps.

Does anyone know of anything suitable for this purpose?

Cheers
Rob

Try LittleSnitch. I use it for any network related permissions I grant my apps. Hope this is what you were looking for. It blocks any outgoing connections you don't want.