Dropover - Mac app for easier drag & drop

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.

Dockside (Open-Source) - Dockside is an open-source tool for provisioning lightweight access-controlled IDEs, staging environments and sandboxes - aka ‘devtainers’ - on local machines, on-premises (raw metal or VM) or in the cloud.

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.

DropPoint - A free and open source alternative to Dropover, that makes dragging and dropping of files seamless. Works on Windows Linux and Mac

Shelfit - Worry less about juggling multiple windows or deciding where you want to store things. With Shelfit you can quickly open up a shelf, drag files in, and then when you're ready just drag them back out.