If you go to the Account Settings page in the navigation bar and click the My Team tab, you will see by choosing "My Supervisors" on the left of the page, the following users that have full access to your Ringy account.
Additionally, joining a company as identified by navigating to the Account Settings page in the left hand menu, and choosing the My Company tab, will grant the company administrator access to your Ringy account. The company administrator will have administrator access, and depending on the configuration of the company settings, possibly full account login access as well. This will be specified when you are joining the company whether they will also have full account login access.