To make sure you're always building off the right set, Plans makes sure you default to viewing the newest revision of each sheet. You can tell if a sheet has past revisions by checking for a dog-eared corner in the bottom right of the sheet. Tap the corner to view an older version or compare two versions of the same sheet. When viewing an old version, the sheet will show the void watermark to remind you that it's been replaced. When comparing the two sheets use the controls to line up the versions and see the similarities in black, the new version in blue and the old version in green.
Upload new sheets in the office and make them instantly available to field supervisors. Overlay versions, and highlight changes quickly for easy revision comparison.