There should be no special instructions needed for Citrix installations.
Technically, if you’re a company, you’re obliged to use the Business plan according to the terms of use. Of course we won’t go after you if you use the Premium version instead – but we may be unable to help you out in situations where the Business plan would have been the right thing to use.
Using a single account does not make sense in most cases, unless the use-case is to share information between the users, but protect against all others. It’s also another violation of the terms of use… A Premium account is for one person on any number of devices.
The Free Plan is available for all though and you can use it in almost any way you want. It does lack some features of course.