Custom app development not available with Standard Plan?

https://www.ringcentral.com/office/plansandpricing.html shows that 'Custom app development and deployment' is an included feature of the Standard plan, however whenever I call RingCentral Customer Service I'm told that I muse have a Premium plan in order to access and develop custom apps.

It also appears as if other features listed on this webpage are either incorrect or have been recently changed.