In your RunSensible account, click the settings icon settings in the main navigation bar.
User Managment is located under Settings > Business Profile
You can Add, Deactivate and Remove users from User Management.

Add a user

Fill in username and then email address and click on “Add User” button.

Deactivate a user:

The deactivated user will no longer have access to the web or mobile applications, but will remain the owner of past Leads, Contacts, Deals and Tasks unless ownership is reassigned. They will be visible on past reports, but cannot be assigned new items
From the “User Management” click on “Deactivate”.

Remove a user:

If you remove a user: all of the user data will be deleted. The deleted user is not the owner of past leads, contacts, Opportunities, Tasks.
From the “User Management” click on “Remove”.