APK Studio is a cross-platform IDE for reverse-engineering (decompiling/editing) & recompiling of android application binaries within a single user-interface. It features a friendly layout, with a code editor which support syntax highlighting for Android SMALI (*.smali) code files.
Instructions:

• Make sure JAVA_HOME point to a valid JDK (JRE may not work)
• You should also install or have ADB in PATH. This can be done on debian{-based} distros as follows:

sudo apt-get install android-tools-adb

You can then download, install & start de/re-compiling
Note: If you encounter any problems, make sure to check Console Output at bottom of IDE to get the output of command which was actually executed by program. Report any issues related to APK Studio here on Github. Please note, an issue with apktool is not an issue with APK Studio. Please verify the context of issue before opening a ticket.

Download:

• Native installers for supported platforms are here.
  

Building (Linux):

• Make sure you have GCC 4.6+, QT 5.2+
• Run below commands in a writable directory

  git clone https://github.com/vaibhavpandeyvpz/apkstudio.git
  cd apkstudio
  lrelease res/lang/en.ts
  qmake apkstudio.pro CONFIG+=release
  # {IF} On KDE 5.x
  export CXXFLAGS="$CXXFLAGS -DNO_NATIVE_DIALOG"
  # {/IF}
  make
  

  More information on building from source is provided in the Wiki
  Features:

  • Decompile/Recompile APK
  • Flexible Keystore & Key-Alias Chooser
  • Automatic Zip-align
  • Syntax Highlighting (*.java; *.smali; *.xml; *.yml)
  • Image Viewer For Resources
  • One-click Install To Device
  • Frameworks Support

   

Todo:

• Code Completion

Screenshots:

 

Disclaimer:
Same as apktool, APK Studio is neither intended for piracy nor other non-legal uses. It could be used for localizing, adding some features or support for custom platforms, analyzing applications & much more.