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.

Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.

Dropover - Mac app for easier drag & drop

Swiftdrop - Swiftdrop is a super simple cloud sharing app for Mac.

Unclutter - Unclutter is an app that is designed to help Mac users bring order to their desktop. Among other features, this powerful piece of software provides quick access to a user's notepad and clipboard.

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