Here's an app for you, creators. It is an html file you can use to randomly display an image from a chosen local image directory on your device. The images in your chosen directory stay offline, they are not shared online by the app.

You can set a timer or choose to manually show the next random image. 

To install the app, just buy it for 0€, install it on your desktop and double click to open it. 
Once opened click the 'Choose folder' button to select your desired image folder. 
Have fun!

You are free to use this app for non-commercial use. Consider it a gift from one artist to another.