Konrád Koller

Do you like to write long articles with many headers? Then this is the perfect plugin for you. This plugin will add a link next to your headers so your user can share your posts pointing to specific parts. Plus a smooth scroll script is also included which will make the overall experience even better.
The package contains a predefined style for Git-like link display but it is hardly recommend to change the style to fit your needs (and your design).
The plugin uses internal cache which may interfere with other cache plugins, if you experience anything strange feel free to contact the plugin author.

ONet Header Linkifier

For advanced users! Github-like header parser for your posts, pages and custom contents. Also lets you fetch TOC for any content.

oue.st

This plugin provides you to add a summary in the top of article, using article’s
<
h3> tags. It also add a “Go to top page” link in each tags.
You can put all the anchor links inside the article wherever you want using a single function : ShowAnchorLinks().
Version française :
Ce plugin vous permet d’ajouter en haut de chacun de vos article un sommaire avec des liens pointant vers chacun des que vous aurez utilisé dans l’article. Il ajoute également un lien “Alelr au sommaire” devant chacun des intertitres .
Vous pouvez ajouter la liste de tous les liens ancres que contient votre article en utilisant la fonction ShowAnchorLinks().

Anchor Links Plugin

Auto add a summary in each article using his  tags.

ONet Header Linkifier vs Anchor Links Plugin