Ok, there's two apk files from ludei's mail, right? One is named as "~debug_signed" and another as "~release_unsigned". Debug one is for the test, so it could be installed in your phone without signing and zipaligning, but Google Store doesn't accept it. You have to create your own keystore file(keystore file is your identity. Keep it safe.) with 'keytool', sign your release apk with keystore file through 'jarsigner', and get it zip-aligned with 'zipalign' program. The tutorial you have linked is really awesome. You should do as it says.
You can find 'zipalign' program in the Eclipse folder. In my case :
and 'keytool' and 'jarsigner' program are in Java folder. In my case :