Jadx is useful for decompilation, yes — it produces the best results of all the decompilers I tried because it works with dalvik bytecode directly (vs convertin

Jadx is useful for decompilation, yes — it produces the best results of all the decompilers I tried because it works with dalvik bytecode directly (vs converting it into regular JVM classes). If I need to patch an apk though, I'd first use jadx to find the place I need to change, but then it's apktool for actual patching in bytecode because it disassembles and reassembles dex files losslessly. Java decompilers aren't intended to produce valid code that you can compile back. Sometimes they do, but it's more of a coincidence. By the way. Another underrated reverse engineering tool is xposed framework. It was never intended to be one, but the ability to inject arbitrary code into any app and install hooks without having to modify the apk is a godsend.