Regular text is only visible to you. Headlines go on the slide.
Unlike popular Markdown slide tools, iA Presenter has a unique approach to displaying written content in Markdown.
Are you looking at its innovative approach with longing eyes? No need to wait with your fingers crossed; the same feature can be achieved in Marp using a plugin.
git clone https://gist.github.com/54a1b07ff41485920d370e864860b8a8.git ia_presenter_style_notes