Here is link to the pull request if anyone wants to try out the changes. Clone with
git clone -b touchscreen-pr-clean https://github.com/rts58/MMM-ImagesPhotos.git
Aside from the touch support, there are a couple of other changes worth mentioning. The original code selected a random image each time a new image was needed. Because I wanted to be able to move backward and forward through the slideshow, it now creates a one-time randomized playlist of all images. This ensures every image is shown once before any are repeated.
Navigation is also available via notifications. If you use MMM-RemoteControl, the app’s module controls provide Previous, Next, and Pause/Resume even without a touch monitor.