First, you must open a file in the project you're working on, press ctrl + alt + t, and you'll get a command prompt in the project's directory.
Requires an open text file to work.
No support for mac or Linux.
No coffee script. Stop using coffee.
No docking possible, yet.
If someone wants to help, they can look into making it work in an atom tab/pane so it's not in an external window.
Good catch. Let us know what about this package looks wrong to you, and we'll investigate right away.