NOTE: Videos were created from two resources. One is audiobooks which were created with Joytan, the other is image clips which were created separately from the app. Video-making feature is not included in the current version of Joytan.
I may only leave this online for a while, since TTS often makes mistakes and may not be so good for students studying a language.
If your language level is high enough to know which ones are wrong, then maybe it's OK, but this video wouldn't be good for beginners.
I created this, using JoyTan, then copying the output folder with the individual files before those files got deleted.
After that, I created a program to load in the individual audio files and displaying the text that I used to create the video files.
Perhaps you could do something like that.