Totals the number of configured extensions, voicemail boxes, ring groups and the like per Domain, with the ability to export all this data to a CSV so you can open it in your favorite spreadsheet software!
This was tested with FusionPBX 5.6 (current master at time of writing) and will likely work on newer or slightly older versions of FusionPBX.
Clone the FusionPBX-Apps repo into the working path after SSHing/Moshing into your server:
cd /var/www/fusionpbx/app
git clone https://github.com/fusionpbx/fusionpbx-app-domain_counts.git domain_counts
php /var/www/fusionpbx/core/upgrade/upgrade.php
Then navigate to Advanced > Upgrade. Run Menu Defaults and Permission Defaults.
Log out and back into your FusionPBX installation.
You will now see Domain Counts under menu Status.