Where, Why & How Do You Use Fing?

I'm curious to know where, why and how people use Fing.  Since I am former (and thus recovering) "I.T. person," the days have long since passed where I need to figure out something in a corporate environment.  I personally use Fing, mainly at home to troubleshoot connectivity issues and once in a while to see if somone tried to hop on our home network.
Where:  Anyone using it in a public space like a coffee shop, airport,etc.
Why did you need to see all the devices on a public network (outside of curiosity).
How:  What problems is Fing solving for you?  Is it replacing something else?