Endnote app icon persists in Macbook launchpad after deleting all files
In the future, try using AppCleaner (http://freemacsoft.net/appcleaner/). The Mac way of removing apps is to just move them to the trash, but that almost always leaves junk behind. AppCleaner helps gather that junk and send it to the trash, too.

Disclaimer: I'm not employed or endorsed my FreeMacSoft, the developers of AppCleaner. I'm just a fan.

Good luck! :)