I can't see any plugin

Plugins on plugins.gitbook.com sometimes shows 0 plugins.

This is a known issue. To stay up-to-date, the plugin store regularly fetches the list of plugins from the NPM registry. It takes some time to reconstruct the list of plugins. During this period, it looks like there are no plugin listed at all. That's something we are working on improving.

Meanwhile, you can always search for plugins on NPM (their names all start with gitbook-plugin)