I am a big fan of paperpile: https://paperpile.com https://paperpile.com I've used Endnote, Mendeley, and Zotero before and found them all to have their own i

I am a big fan of paperpile: https://paperpile.com https://paperpile.com I've used Endnote, Mendeley, and Zotero before and found them all to have their own issues. Paperpile is not perfect but it shines in a few places and I really like it. The chrome plugin adds an 'add to paperpile' button to places like google scholar making it easy to add citations. It also is designed for writing in Google Docs and makes it very easy and quick to add citations. For some, Google Docs may be a dealbreaker, but if you need to collaboratively write/edit a manuscript it's much better than the alternatives in my opinion (esp. because everyone can write/edit at the same time).