In the Argus Hub, it is easy to see when any of your users last logged in online and able to export their usage over the last 90 days.
From the sidebar select Settings, then Users and Drivers.
In the Last Web Sign In column, you will see the most recent occasion each user logged in. Any logins that day will be listed as X hours ago, then any logins longer than a day will be listed in days.
This feature shows the last online login, Argus Android and iOS app usage is not counted, and is for Argus Hub users only - it does not show a 'Drivers' last sign in.
The report can be exported in CSV for the last 30 or 90 days of user activities, that show each and every sign-in over that period.