Timekeeping functionality is provided by the Service Manager. This can be done by clicking the Start/Stop button or selecting Start/Stop Timekeeping when you add a Response.
Service Tickets with active timekeeping are highlighted in yellow in the list view. A warning message is displayed when you close a ticket with an open timekeeping record.
Check Menu (button) > Show Timekeeping Hr/s and then click the View button to view the actual hours logged against SM Tickets in the List View.