The evolutionary weapon that's helped humanity climb to the top of the food chain, and the key digit in using the modern smartphone.
It seems a waste then that 80 per cent of our fingers aren't involved in interacting with our gadgets - unless you've got one of these.
The HandyCase straps to an iPhone or iPad and allows users to tap, swipe and pinch with their device from behind without obscuring the screen with their hands.
Your gadget doesn't actually become transparent - rather the HandyCase will sense where your fingers are positioned on the rear of the case and superimpose a faint digital handprint on your screen to show you where you're tapping.
The opacity of this hand can then be adjusted with an accompanying app - allowing you to remove the impression of your fingers altogether once you've mastered it.
The internal battery is good for around 20 hours, putting it on a par with the majority of Apple's gadgets.
Currently climbing its way toward a $100,000 Kickstarter goal, you can order a case for an iPhone 6 for $99 (£65), or for an iPad Air for $149 (£97).
Just don't tell them that the PlayStation Vita has been using a back panel for a while now - they seem to think they're the first to crack it.