Wow, I’ve never heard of it but it looks interestig thanks! For anyone reading this, here’s some links:

• Typst’s official webpage
• GitHub Repository

Apparently I also found someone made a mobile app editor for Typst, but it’s in another app store called Accrescent (I don’t know if it’s safe? I will do some searches on it to get to know about) The project BeauTyXT official website, GitHub Repository (.apk available on Releases page)

TeX is a typesetting language. Instead of visually formatting your text, you enter your manuscript text intertwined with TeX commands in a plain text file. You then run TeX to produce formatted output, such as a PDF file. Thus, in contrast to standard word processors, your document is a separate file that does not pretend to be a representation of the final typeset output, and so can be easily edited and manipulated.

Source (tug.org)

More info on LaTeX