For quite a long time, I have been cleaning, sorting, re-framing (when needed) and also a bit documenting color slides from the late 50s up to the 70s. Family property. A light table is nice to have to inspect both positive and negative film.
For a while I was an iPhone user, and there is a simple light table app to it, called ... LightTable! I do not use iPhone anymore, but recently I needed a light table again. There are light tables as a separate product (since long before the "digital era"), but I did not want that.
I did recall the app, and I have an old iPhone 4. Hoarding stuff... "you never know...". Bad battery but no problem for this use. No sim card. I apparently still have an apple id mail adress, so I downloaded the app. After that the phone is never connected to Internet, and I use it just for this (i.e. rarely). Together with a loupe. No scanning.
I guess it would be not too hard for a programmer to make a light table app that does only that: turn the whole screen into white. As for such skills, I do not have them.
There are those things that look like a small old telly that you can look at slides in. But in my experience, paper framed slides can get stuck in them. As for paper frames I have quite a collection of different looks and brands. Might post a pic of some one day. Next year maybe...
Here is how it looks (not the best photo):
An old iPad might be better. A dedicated light table even more, obviously. But this was free for me.