"I wanted a tool for screenshots/GIFs to supplement apps like Slack, but nothing on the market had the mix of speed and features we were looking for."

Did you have a look at Jumpshare (https://jumpshare.com)? We offer video recording, screenshot capture + annotation, file sharing, and more - all wrapped up in an easy to use Mac menu bar and Windows system tray app. On quick capture (or upload), it copies a shareable link to the clipboard so you can quickly share it anywhere. :-)