APK Tool

APK tool can be used to decompile android APK files, providing access to readable XML files (among other things). Download the apktool jar along with the installer for your OS. Unpack everything to one directory, you should have 3 files altogether (aapt, apktool, apktool.jar). Once you have cd’d into your folder containing the apktools files, the following command will decompile the desired APK to a folder within this current folder;
$ ./apktool -v d ~/Desktop/target.apk