Create "nagios" and "addon bar" addons for Firefox Quantum.

[NilimaC04]

As both of them are very usefull add-ons.
The Addon Bar: Gives you a place to put all your add-on buttons without over-crowding the navigation bar.
Nagios Checker: The statusbar indicator of the events from the network monitoring system.

[iamVP7]

@NilimaC04 it will be helpful if you can share the legacy addons link if you have anything in your mind.