What additional tools are available for Facebook Analytics?

I've recently started managing a handful of groups social media feeds, especially Facebook pages. For the most part I have handling it from communications / marketing point and generating interesting and creative content for the feeds.

Now, I want to be able to dig a deeper in the data behind what I am doing and understand what groups I am making progress with and a new client is asking for better metrics.

What tools are available out there to help me better understanding audiences and analytics of the pages I manage? They don't need to be free tools I do have a bit of a budget here.

Thanks!