This addon is logging addons (include locales and plugins) status change(install, enable, disable, uninstall) to remember WHEN and WHAT addons was installed and uninstalled.
Default log file name is "AddonStatus.log" that stored into your profile directory.
A kind of Addon Scope:
Add-on is installed in the current profile directory.
Add-on is installed somewhere specific to the current user (all profiles of the logged-in user).
Add-on is a part of the current application (Installed and owned by Firefox).
Add-on is installed somewhere global to the system (installed for all users of the computer).
A combination of all the installation scopes.
"The Future of Developing Firefox Add-ons | Mozilla Add-ons Blog"
"Add-ons/developer/communication - MozillaWiki - Upcoming Changes in Add-on Development"https://wiki.mozilla.org/Add-ons/developer/communication#Upcoming_Changes_in_Add-on_Development