Nick Lee was able to run Android on iPhone with the help of 3D printed case. The case is being used as the phone, while the iPhone is being used as an external display. Last month Lee was also able to run Windows 95 on Apple iWatch.
Lee built an app that helps to connect iPhone with the 3D case. Once the case is connected to the iPhone’s Lightning port, you can launch directly into Android. The case also features an opening for an SD card, as well as HDMI and USB ports.
You can get more details on Lee’s Medium post.