Dropzone - If you want your file uploads to work even without JavaScript, you can include an element with the class fallback that dropzone will remove if the browser is supported.

ScreenTray - A better way to capture, annotate and share screenshots

Yoink - Yoink is a website that makes it easier to drag and drop images and text from one screen to another. It's a straightforward site with help along the way if you aren't sure about dragging and how to place your content.

Marker.io for Slack - Turn screenshots into Slack messages ✌️

Droplr - Droplr is a tiny application that aims at helping people share things easier.

Weava - Workspace to highlight, organize & collaborate on your research articles.