What is the Extension Settings Module used for?

The Extension Settings Module is actually a reports module.  It will show you each extension on your system and whether that extension has Call Waiting, Do Not Disturb, Call Forwarding, VMX Locator, Follow-Me, and other features enabled or disabled.  

This module may eventually be moved to the "Reports" tab and be renamed "Extension Settings Report."

How Do I Get to the Extension Settings Module?

To access the Extension Settings Module in FreePBX 2.10 and later, access the graphical user interface using a web browser.  Click on the "Settings" pull down menu at the top and then select "Extension Settings".