I was lucky enough to be in on the alpha and beta of Adobe Experience Design CC (the design and prototyping app formerly known as Comet, which... just seems cooler).
This is a quick prototype, done within an hour or so, of an idea I've been working on. So far I haven't found a good, non-code-based tool with which I can show the key interaction of moving and pairing list items, and I'm discovering limitations of Adobe XD (which I hope will be removed as they further develop the application) – but the act of making and prototyping gave me some insights into how the interactions could work better for the user, and some feature ideas that popped up in the process. So, cheers to prototyping! (Click image to go to interactive prototype.)