Apktool will work. You don't even need to know the keystore to extract the source code (which is a bit scary). The main downside is that the source is presented in Smali format instead of Java. Other files such as the icon and main.xml come through perfectly fine though and it may be worth your time to at least recover those. Ultimately,
you will most likely need to re-
write your Java code from scratch. You can find apktool here. Simply just download apktool and the appropriate helper (for Windows, Linux, or Mac OS). I recommend using a tool such as 7-zip to unpack them. Download Here: http://code.google.com/p/android-apktool/
