Forget UI design, let the user decide instead.

I absolutely love this concept from Marc Exposito which combines the best of IFTTT and augmented reality to allow you to quickly, simply and visually control Internet-of-Things enabled devices. I've yet to find any IoT gadgets that actually warrant a purchase (personally) but as the field expands and becomes more ubiquitous, apps such as Drawit will in turn become more and more powerful. These are the types of problems and subtle interactions that I can see the IoT, tablets, wearables etc. really embracing in the near future.