If you are a nexus 4 user, you must be disappointed when Google skipped Android 6.0 Marshmallow update for Nexus 4. Even though Nexus 4 appears quite capable in terms of hardware, Google choose to skip Android 6.0 Marshmallow update for it as the device has exceeded its official support period of 18 months. The only hope for Nexus 4 users to get an update, was to get it from Android developers who could port it in the form of custom ROM.
And Developers have proved the users right. The first unofficial port of Android 6.0 Marshmallow for Nexus 4 is now available for you to download and test it. Developer Dmitry Grinberg has released the first unofficial port of Android 6.0 for the Nexus 4. He has made available a pre-built AOSP Marshmallow image to download. Interestingly, it also includes LTE radio. The download link is available on the developer site linked earlier in this post. As per developer, WiFi, Bluetooth, GPS, NFC, Cellular and Camera works.
The unofficial port is based on Android Open Source Project (AOSP) code for the 2013 Google Nexus 7 which has similar processor to Nexus 4. The developer has not provided any download links for Gapps (the basic google services like Playstore) and you need to find that on your own. At the moment, there is no Gapps download link available anywhere for a Gapps package file for Android 6.0 marshmallow.
We will be making a detailed tutorial soon, on how you can install the custom ROM or this unofficial port of Android 6.0 Marshmallow on Nexus 4. Stay tuned.
Source : Reddit