leemon

Add external media from a <a href="https://codex.wordpress.org/Embeds" rel="nofollow ugc">supported oEmbed provider</a> (YouTube, Vimeo, SoundCloud, Twitter, …) to the media library

Add External Media

Meets expectations

Great plugin, thanks! I just miss the feature of adding it directly in the WordPress Media

Great plugin

Dan Griffiths

Adds a robust third-party product system to Easy Digital Downloads. When activated, adds new fields to the Download Prices meta box allowing you to specify redirect details.
External Products is based on the extension of the same name by WebDevStudios.

Easy Digital Downloads – External Products

Was looking for exactly this: an option to add third party plugins on my own EDD shop. 

Perfect

Adds a robust third-party product system to Easy Digital Downloads

Add External Media vs Easy Digital Downloads – External Products