JADX - Java source code from Android Dex and Apk files

jadx[-gui] [options] <input file> (.dex, .apk, .jar or .class)
options:
 -d, --output-dir    - output directory
 -j, --threads-count - processing threads count
 -f, --fallback      - make simple dump (using goto instead of 'if', 'for', etc)
     --cfg           - save methods control flow graph to dot file
     --raw-cfg       - save methods control flow graph (use raw instructions)
 -v, --verbose       - verbose output
 -h, --help          - print this help
Example:
 jadx -d out classes.dex