You have to have your own private key and perform the build using this key before you publish your application though. So far the support for such a build was missing in nbandroid but this has changed. The latest snapshot adds a wizard hooked to an action available on project context menu to export signed application package. Values from project's properties files are used to assist you. Namely
key.aliasare two basic properties to determine the location of keystore and name of the key used to sign the application. You can try it using the bits from continuous build and it will propagate to the stable update center in a few days if no bugs are reported.