This is a modified version of Meta's Instagram application for the Android platform with Messenger chat features and developer options enabled.

To do that, I downloaded an Instagram APK from apkmirror and decompiled its dex files present in it (Aside: An APK file is basically a zip file containing the app's code and other resources such as images, strings, etc) In this context, decompilation means turning the Dalvik bytecode into a more human readable format called Smali language. This is achieved by using the apktool decompiler.

To enable the chat features, I had to search through strings in the smali code and inspect the Instaprefs Xposed module on a rooted Android device.

I was able to imitate what Instaprefs does to enable developer options by writing it in smali code. This was a pain in the neck frankly, given that smali code is essentially assembly. It was definitely fun though!

Find out more here.