The fact that the Lumia 520 and the 525 can run Android is not a secret. We have already covered the phenomenon before, but this time, the now ancient phone runs the latest Android version available and is a part of Android Nougat's small market share.
The Lumia 520 was released almost four years ago and did not receive an official upgrade to Windows 10 Mobile. However, it seems like it may enjoy the little green robot instead of a blue flag. The system that is running on the phone is a Resurrection Remix 5.8.0 ROM based on Android 7.1, which is the latest version directly from Google, with some modifications and extra features.
The device may not be performing like a flagship device meant to run Android, but it's still incredible what its relatively weak processor can accomplish. The optimization of the operating system may also play a role in the performance, but the biggest factor making it feel sluggish is its instability. The project is far from a stable release and this affects the demo shown below:
The ROM features everything you would expect from a Nougat installation. It even features the split-screen functionality that Android borrowed from Windows 8, meanwhile, Microsoft doesn't seem to be interested in putting the feature on their own mobile operating any time soon.
Because this is an Android Open Source Project (AOSP) based ROM, it doesn't include any of Google's own apps, but it shouldn't be all too difficult to get the to run, as the Play Store, Chrome, Messenger and other G-Apps are easily flashable on almost any Android system.
The Lumia 525 appears to run much more stable and much smoother, however, this could be a coincidence and it is likely not in a "daily use" state (We recommend that you mute the video):
With these devices running so well, it's just a matter of time before the project get's a public release. Many users would love to run Android on their Lumia phones, for reasons unknown, and this project may help people with older phones to get them in a usable state again.
But if you really think about it, if you're still using a four-year-old budget device running a dead operating system, it may be a good time to finally upgrade.