Administrators have all the privileges and access to all the settings, data and features in Insightful. This is why there is no management of Admin permissions available in the application - they will always have all of them by default.
To add another Admin for your Insightful account, do the following:
On the sidebar select Settings → User Management,
Make sure that you are on Admins tab,
Click on the Add New User button,
In the drop-down menu click on +Admin,
5. A new Admin window will appear and all you need to do is enter the Name and Email of the future Admin. Insightful will send them an email with further instructions.
Admins will use their credentials to log in on https://app.insightful.io.
Admins, Managers, and Clients do not need Insightful installed on their computers to log in and view data; as such, they do not add towards billable license count.
If you wish to "upgrade" a user to an Admin level you will first need to remove them as a user in their current role (employee, manager or client) and subsequently add them as admin.