Why need to activate s4u plugin when it should be free?

Fillejaco

I'm running SU18, and downloaded S4U connect from sketchucation.
I thought this one was free, at least it is on extension warehouse.
So here comes a stupid question maybe...

After installing, when trying to run it, it says two things...

"you need to be connected to the internet"
I'm asked to type my email and authorization code.

Why is the activation code required when it's free?
I thought it was just to start up and run it..

Have I missed anything here?
Is it not a free plugin ?