Github Plugin Search (great tip, but only use this when you know what you are doing)
This is aplugin created by Paul Clark. As the name implies, this plugin allows you to search and install WordPress plugins from Github.
(Github is also used for Bitcoin exchanges and so on, it is a great technology, but everybody can use it as they want)

Once installed, you can search andadd new Plugins from Plugins > Add New menu as usual. But as this plugin is still undergoing development, it replaces the Plugins search result entirely with a list of plugins found in Github.

In this example below, I searched for “bootstrap”. And it returns several results.

Be careful though of what you install as plugins are not moderated. There may be a chance that malicious codes may allow infiltration of your website.