Smartapp Multi-party Sketch™ lets you view & markup drawings, BIM, photos and more in a multi-tab, multi-party, presence aware real-time Sketch™ with built-in chat, comment, LiveHuddle & LiveLink audio/video communication between the jobsite & office team.
More Sketch™ help:
How to Open Files in Smartapp Sketch™ - Mobile?
How to Open Files in Smartapp Sketch™ - Desktop?
How to Create a Sketch Template