LordPretender

This plugin allow you to add files into your media library without having to upload them. So, you will be able to share, for example, your files into your Google Drive. 
This also save you steps to download the image to local computer and upload again to your own WordPress.
<h4>Features</h4>
<ul>
<li>Automatically downloads and adds the file to the media library.</li>
<li>After the uploading is successful, you are redirected to the edit screen</li>
<li>A new dropdown list is available in the media library to let you display only uploaded files, not uploaded files, …</li>
</ul>

Add Media from URL

large chunks of code taken from the much better original here:

https://en-au.wordpress.org/plugins/lh-add-media-from-url/

IMO it unethical to use this plugin

A crappy clone of the original

Let you add media files into your media library without having to upload them.

scribu

mustela

<a href="https://codex.wordpress.org/Press_This" rel="nofollow ugc">Press This</a> is neat, but wouldn’t it be a lot neater if you had access to all the functionality you have on the normal post editing screen?
With this plugin, you will have access to all the meta boxes, not just Categories and Tags.
Also, plain URLs are inserted in the post content, letting the <a href="https://codex.wordpress.org/Embeds" rel="nofollow ugc">Embeds</a> feature do the rest.
Important: After activating the plugin, you will have to re-add the bookmarklet, from WP Admin -> Tools.
Links: <a href="http://scribu.net/wordpress/press-this-reloaded" rel="nofollow ugc">Plugin News</a> | <a href="http://scribu.net" rel="nofollow ugc">Author’s Site</a>

Press This Reloaded

Generates warning, and breaks press this button



Generate warning, and breaks press this button

Press This, using the regular Add New Post screen

Add Media from URL vs Press This Reloaded