It would be beneficial for the WHMCS admin area navigation to be more navigable via keyboard commands (eg. tab and shift-tab). Currently the main navigation options such as Add, Clients, Orders, Billing...Automation Status, Configuration etc. can only be accessed with use of a mouse.
Please consider making it navigable with keyboards and adding appropriate descriptions/alt tags.
Any mouse-driven menu either needs to have code to expand the menu with the enter key, have a index page that lists the menu items as a contents page with hyperlinks to the pages, or a hook.