Yes, "admin" is counted as one user.

If you don't want to use the "admin" user, you can assign any other user to take over the administrative rights, and then you can deactivate "admin". For information on how to manage users, please refer to:
http://www.dynamsoft.com/help/SCM%20Hosted/Admin-Explorer/Users.htm

Steps:

1. Add a new user by clicking the "Add" button. (Optional)
http://www.dynamsoft.com/help/SCM%20Hosted/Admin-Explorer/Add-User.htm

2. Assign the new user or another active user to the "administrator" group by highlighting the user and clicking the "Member of" button.
http://www.dynamsoft.com/help/SCM%20Hosted/Admin-Explorer/Group-Members.htm

3. Deactivate "admin" by clicking the "Edit" button and then uncheck the "User is active" option.
http://www.dynamsoft.com/help/SCM%20Hosted/Admin-Explorer/Edit-User.htm