As the app offers a single catalog per account, branches can be managed by categories, if wanted but different businesses need separate accounts.
Each account must have a different e-mail address, it is not possible to use the same e-mail twice in Kyte. You can access as many accounts as you want on your device but you will have to log out of one to log in to the other.
The PRO plan subscription is also done per account, so you will have to enable it separately for each one but all users registered in the account will have access to the resources.