Parcel Tracker Concept For elementary OS

Great mockup.
I will probably implementing this. I have a good idea how to access most courier all over the world.
Can you elaborate a little bit on the workflow...
What is behind the gear menu? how to show the comment popup? how to select the necessary courier (some tracking number can be automatically mapped to a courier but some are the same for various courier, so it must be selected by the user)? What are the colored badges on the right side (what says the color, what the number)?