No, you wouldn’t have to create an account or App to manage each one of them. You can have an Admin account for you (only one license) and from there create an App (say your company’s name, coloring scheme, logo, etc). After that, you may create different Organizations for each company that you will be managing. Then, you can create End-Users, which are the equivalent of an account for the companies to log in and view their data. These End-Users will only be associated to the Organization (Company) they belong to, so they can only view the data from their Organization.
Depending on the requirements of the companies that you will manage, another option that you could benefit from is having the Admin account, but with multiple Apps (one for each company to manage) and then have the same Organizations and End-Users structure explained above. This would allow you to add Custom Branding to each company.
Here’s an article which gives a better glimpse of what Apps, Organizations, and End-Users are.
It’s important to note that these functionalities are available from our Professional license and above. For more information on our Plans, please view our Pricing Website
Does this make sense?