Reverse engineering & modifying Android apps with JADX & Frida

I get a lot of emails from users who want to know exactly what their favourite Android app is doing, and want to tweak and change how that works for themselves. There are some great tools to do this, including JADX & Frida , but using these is complicated, and every reverse engineering problem has its own unique challenges & solutions. There’s few good guides to getting started, and even fewer guides on the advanced tricks available.