How can I convert an Android app to an app for Ubuntu for phones?

view story

http://askubuntu.com – How can I change from commercially developed app(XXX.APK) for android phone(ex, GalaxyS, GalaxyNexus,etc) to App for phone installed ubutun OS? ( How can I change android APK to app that can be used in Ubuntu phone? ) - Once ubuntu for phone is installed , it is automatically changed? or it is needed any other tool or procedure. - If tool is needed, let me know tool name and procedures . plz send user manual too. (HowTos)