Developer Nick Lee has earned himself a reputation for putting weird and wacky operating systems on Apple gadgets, including Windows 95 on an Apple Watch. Now, he's gone the practical route of bringing a full-fledged version of Android to the iPhone. There's just one catch: you need a special, 3D-printed smartphone case to make it work.

Lee decided to clone the Android Open Source Project (AOSP) and make a custom version of Android Marshmallow he could run on a board he bought himself. He then 3D printed an iPhone-sized enclosure he found on Thingiverse, and combined the board, a battery, a boost converter, and resistor to make a lightweight case. At first, it was quite bulky, resembling a brick you'd be more likely to have seen in a cellphone store 15 years ago.

But after slimming down the design, Lee was able to craft an enclosure not too much larger than your standard smartphone battery case. He also included openings for HDMI and USB ports, as well as a SD card slot. In his YouTube demonstration, Lee appears to slip a light sheet of plastic over the components before placing an iPhone on top.

He also appears to boot Android by way of a custom Tendigi app on the iPhone's home screen. Tendigi, where Lee works as CTO, is a mobile design and development studio in Brooklyn, and Lee uses its iOS app to communicate with the case and load his custom version of Android on an iPhone 6S's display. The whole process here took many days, Lee says, and it's not exactly practical. But it is a fascinating look at both the ingenuity it took to perform this feat and the lengths at which you have to go to get even a custom open-source version of Android running on Apple's flagship phone.