fold-and-focus

Fold and Focus helps you navigate Org, Markdown and Emacs Lisp files with
focused attention: one thing at a time. You can navigate by heading or
by defun, optionally narrowing to it as you go.

As you navigate, the heading you move to will be recentered, so you'll
always have it at a fixed position. Its contents will be shown.

The heading you came from will be folded and won't distract you.

For all the details, please do see the README

Open it easily with:
  (find-file-read-only "README.org")   <--- C-x C-e here¹

or from any buffer:
  M-x fold-and-focus-see-readme

or read it online:
  <https://flandrew.srht.site/listful/sw-emacs-fold-and-focus.html>

¹ or the key that ‘eval-last-sexp’ is bound to, if not C-x C-e.