WTF?! Smartphones are technical marvels: tiny yet powerful computers that fit inside our pockets. But what's the one obvious element they lack? A terrifying robot finger that's able to drag them around and caress your wrist in a way that definitely isn't creepy, that's what.

The MobiLimb is the work of human-computer interaction researcher Marc Teyssier and his colleagues from Paris-Saclay University and Sorbonne University in France. The device clips into a smartphone via the USB port, and is powered by an Arduino microcontroller and five servo motors within its 3D-printed shell.

"In the spirit of human augmentation, which aims at overcoming human body limitations by using robotic devices, our approach aims at overcoming mobile device limitations (static, passive, motionless) by using a robotic limb," writes Teyssier.

In the video, we see how the robotic digit can drag the phone along the floor like some kind of horror movie in which a handset becomes sentient and starts (slowly) stalking its owner. In reality, those of us who are too lazy to walk across a room to retrieve our phones may appreciate this function.

The MobiLimb is also able to stroke the user's wrist as a response to a positive emoji sent by someone, and you can even use a rubber skin that makes it look like a human finger, which is where people might start finding other uses for the MobiLimb---remote prostate exams, perhaps?

Additionally, the finger can double as a joystick, a grip, and a stand. And it can be programmed to tap on a surface or shake whenever you get a notification, which may negatively affect your mental state faster than seeing a phone dragging itself along the floor. The MobiLimb can also draw, act as a torch, and perform many other tasks, but the highlight could be the furry sheath that turns it into a digital cat---perfect for feline fans who hate emptying litter trays and the smell of cat food.