Yes, you can add as many users to your account as you wish without any charge, and you can fine tune the access permisions that you grant each on of them. If you go over to the demo siteĀ you will be able to log in as a few different users with different permissions, e;g. CEO, Maintenance, Marketing Assitant, Tenant Relations Manager.
If you login as Catalina (CEO), and then go over to Manage -> Admins you will see options to add new users, and also to set their authorizations. Feel free to play around with them on the Demo site.