It is currently not possible to subscribe to a folder within the BIM 360 mobile apps. Many users that are in Construction are only accessing BIM 360 with an iPad, so having the ability to Subscribe to a folder through the app would help keep them informed of any changes.
Alternatively, or in addition, if Admins could subscribe Project Members to folders (by Role for instance), it would help Project Admins create a consistent notification system for the users. Add it to Forge as well and it would be lovely.
Thanks!