https://www.makeuseof.com/old-android-tablet-replaced-expensive-gadgets
A portable monitor
GlideX turns it into a portable monitor
A free Stream Deck device
Create a remote macro control deck for Windows
A digital photo frame
Apps that turn your tablet into a photo slideshow device
The real challenge, however, was finding an app that would automatically rotate photos as slideshows. After trying several options, FoToo turned out to be the best option considering the price and features on offer.
FoToo is a photo frame slideshow app that can show your photos from cloud storage (Dropbox, Google Drive, Google Photos, OneDrive, Local Network) or your tablet’s gallery. The free version of the app is limited to a single pan-style transition, which, I must say, is not the prettiest.
However, for a few dollars, you can upgrade to a Premium version for non-stop slideshows, unlimited skips, over 15 transition effects and the current date and time stamp that gives your tablet the authentic photo frame look. You can also schedule to auto-start the app and slideshows, and a timer to save battery. Honestly, I think the upgrades are worth the price.