apktool 2.3.1+dfsg-1 (amd64 binary) in ubuntu cosmic

 A tool for reverse engineering 3rd party, closed, binary Android apps. It can
 decode resources to nearly original form and rebuild them after making some
 modifications; it makes possible to debug smali code step by step. Also it
 makes working with an app easier because of project-like file structure and
 automation of some repetitive tasks like building apk.