Early access accounts allow you to control which Brightpearl accounts are authorized to connect to one or more of your apps whilst the app is in alpha stage. Once an app has been installed on an account you will see it in the customer accounts list for the app.
Once an app is in beta or released, installs will be made within the app store and so new accounts won't need to be added as early access.
Developer level early access accounts
Adding early access accounts against your developer record will mean those Brightpearl accounts are authoized to connect to any of the apps you create.
App level early access accounts
Adding an early access account against an app will mean those Brightpearl accounts are authorized to connect to that single app.
These are the accounts which have the app installed.