Plans can be rotated from the thumbnail view by putting a checkmark in the upper left hand corner of the image (or images), and clicking on either rotation icon on the right hand menu
You can also rotate plan individual pages by clicking the 3 dots next to the plan page name and selecting Rotate Page.
NOTE: Only blank plans can be rotated. If the plan has a takeoff or mark-up, it would need to be deleted to rotate the page
TIP: You can select multiple thumbnails at one time. Press Shift on your keyboard and put a checkmark in the corner of the first plan. Then click in the center of the last plan (click View, instead of putting a checkmark in the corner). This will select all the plans in-between.