I find the title misleading.
typst.app is not a Latex editor. typst has its own syntax and own compiler to generate PDFs.
the cli is FOSS (theres a great plugin for vscode), typst.app is their SaaS Overleaf-equivalent to collaborate on papers. you write .typ, not .tex files. arguably a more modern and easier to read syntax. :)
can recommend if you want something simple. its not there yet in terms of featureset, but its getting there. also its quick and the UX is leagues ahead of latex
rfc3339 my beloved