Technical questions: what are flic buttons?

[flic e]

I can't really see any low level documentation on the flic or the flic2, only how to connect it to a smart phone to set it up.

So i have some questions:

What does this device actually do? It's bluetooth, so is it pairable unconditionnaly, (in the same was as a bluetooth mouse for example) or do i need an app and an account with someone to actually use it.

I just want to pair it with a my device and then have some script do stuff on the bluetooth host on connection, like i can with a standard bluetooth device. Is this possible, or does the button only pair with a phone and an app?

Do we know what the flic2 will do? What are the tech specs (ideally a datasheet) for this button?
Is there code on this thing that we can look at?
Can I write some code to be executed on the button?