Open-source, cross platform Qt based IDE for reverse-engineering
...It features a friendly IDE-like layout including code editor with syntax highlighting support for *.smali code files. If you are just willing to quickly decompile an Android app, you can make use of DeAPK - Online APK Decompiler which lets you decompile an Android app using apktool and jadx.
The aim of this project is to develope a decompiler for java which is platform independent and has options to obfuscate the class file also.
The project takes class file as input and decompiles it and provides the source file.