I use 500x.com , there is free and paid plains.

Portraits in studio. How to use a flash meter to setup the lights and how to direct a model. The most difficult part was directing the model.

I use an old Android Samsung 10" tablet that I have, but you can bought a low price 10" android tablet , just make sure it support a SDcard to store your photos.

Mine runs a very obsolete Android 4 something, very low specs for a modern tablet but to run just one app it is fine.

On the tablet I’ve installed a program named Fotoo - Photo Frame SlideShow it can show photos from internal memory, sdcard, Google Photos, DropBox and has several transition effects, option to display date/time.