i am trying to build android game from this libgdx based games but the android app crashes when ported to android game the libgdx code i downloaded from http://rengelbert.co
Please try this and see if it solves the crash:
Go to the properties for the Android Project, make sure that the Jars and the Desktop Project are being exported. Check that Java Build Path -> Order and Export looks like this:
If you want to use a different Android version than 4.1 that's fine (I just don't have other versions installed so I changed it to 4.1).