I created a very simple and lightweight background wallpaper module. It also exposes 3 URLs to control your wallpaper using your devices like phone and smart watch gestures.
Here is the link to my github repository
https://github.com/sumitnsit/MMM-Wallpaper
Control Slideshow using API
Remote URL Description
http://{IP Address}:8080/next Loads next wallpaper and pauses the slideshow for 30 seconds
http://{IP Address}:8080/last Loads previous wallpaper and pauses the slideshow for 30 seconds
http://{IP Address}:8080/resume Resume the slideshow if you want it to resume before 30 seconds pause.
Control slide show using iPhone’s Shortcuts
You can create shortcuts on iPhone’s Shortcuts app to control the slideshow using your iPhone
Create a new shortcut
Add Get contents of from actions and add URL for next/last/resume.
Be a magician in font of MagicMirror and control wallpaper with your hand gestures.
Go to Settings > Accessibliity > AssistiveTouch > Hand Gestures
Assign gestures to shortcuts created ealiear.
Tap > Last
DoubleTap > Next
Clench > Resume