Unflip

Unflip is a small-sized add-in designed for Microsoft PowerPoint, designed for users who want to fix presentations with flipped images, issues caused by the flip parameters when creating files with older PowerPoint versions. It basically installs a button in your application that you can click to instantly flip pictures to their correct position.

The downloaded package includes a .ppa file that you can just double-click to open in Microsoft PowerPoint. If the program is not associated with this format, then you can find the Add-ins section in the Tools menu, click Add new and pick the Unflip add-in.

Next, you can open a PowerPoint presentation, go to the Add-ins tab in the ribbon bar, find the Menu Commands section, and click Enable Corrective Flip. The change should be immediately applied to the file. To make it permanent, it's only necessary to save the original file or create a new one.

If the add-in wasn't loaded, then you should verify the macros settings (in Tools > Macros > Security) and decrease the security level that prevents unsigned add-ins from getting loaded in PowerPoint.

You must have at least Microsoft PowerPoint 2000 to be able to use this add-in. It also works on Office 2016.