Usage is a Storefront extension.
It makes the Storefront users with the administrative privilege see a monthly overview of the usage of all of their Storefront deployments.
Please see the Setting Up page.

16/12/2021 Version 6.0
The usage overview now displays the pricing package and two options that display either this or last month's figures.
All of the pricing packages now see the overview of all of the used Storefront deployments.

20/01/2021 Version 5.4
Admin Visibility option introduced.

22/08/2019 Version 5.3
The first documented version.