Mainline's vertical images, taken from their web site, are automatically rotated to the required horizontal alignment. (v2.09)
Slide show button added. Select the image area and hit the Slide Show button and the favourites will be applied to the image at the rate set in Options.
Switch off grid in viewfinder to get camera aligning cross hair.
Alt-M Maximise the image to the display window.
2nd monitor can be above/below first monitor, as well as side by side.