[Made by indie developer]
You never think this is even possible.
Magic PiP is an app that can let you view all kinds of stuff in the PiP window. And it can float above other apps, almost like a split-screen!
Contents supported:
Multiple Images / Video
PDF / TXT
PowerPoint Slides (.ppt / .pptx)
Texts from the clipboard
Web page
Clock / Stopwatch / Timer
Counter
Allow open all the stuff from the share sheet.
Allow turning pages in the PiP window.
Also an auto page-turning feature for reading TXT files.