The MSDN article Configure an environment for apps for SharePoint contains the statement "Use a farm account for the SPManagedAccount...", and the Powershell examples for creating the App Management and Subscription Settings SA contain the placeholder "<farm account>" . I am hoping that this is not accurate, and that it is not required to use the farm account for the App Management or Subscription Settings service applications.
Note the portion of the same article that describes how to create an App Managment service application using the Central Administration GUI does not refer to "farm account." It is only in the section on using PowerShell.
It may be that the author considers "a farm account" to be synonymous with an SPmanagedaccount for the farm. But "farm account" in the SharePoint world has always referred to THE unique account used to create the farm.
Can anybody clarify this?