I’ve been wanting to try to decompile some Android applications for a while, and I finally got around to experimenting with it. I don’t plan on becoming an expert, and my time was severly limited.

Googling I found some answers on stackoverflow: answer #1, answer #2 and this repo on github

Attempt #1 - Simplify: Generic Android Deobfuscator

git clone https://github.com/CalebFenton/simplify
sudo apt-get install gradle
gradle shadowJar

Attempt #2 - jadx: Dex to Java decompiler

git clone https://github.com/skylot/jadx
gradle dist
cd ~/github/jadx/build/jadx/bin
./jadx-gui

At first, I had issues building jadx:

Could not find method jcenter() for arguments [] on repository container

But that was quickly overcome by the hints from stackoverflow

And I also realized that I had been using the wrong (old) version of gradle

[ Mon Aug 24 22:35:01 ~/github/jadx ] gradle -version

------------------------------------------------------------
Gradle 1.4
------------------------------------------------------------

Gradle build time: Monday, September 9, 2013 8:44:25 PM UTC
Groovy: 1.8.6
Ant: Apache Ant(TM) version 1.9.3 compiled on April 8 2014
Ivy: non official version
JVM: 1.7.0_75 (Oracle Corporation 24.75-b04)
OS: Linux 3.13.0-37-generic amd64

And what I really wanted was a newer version of gradle

[ Mon Aug 24 22:40:11 ~/github/jadx ] ~/tools/gradle-2.6/bin/gradle -version

------------------------------------------------------------
Gradle 2.6
------------------------------------------------------------

Build time:   2015-08-10 13:15:06 UTC
Build number: none
Revision:     233bbf8e47c82f72cb898b3e0a96b85d0aad166e

Groovy:       2.3.10
Ant:          Apache Ant(TM) version 1.9.3 compiled on December 23 2013
JVM:          1.7.0_79 (Oracle Corporation 24.79-b02)
OS:           Linux 3.13.0-37-generic amd64

jadx-gui screenshot