After install latest XamarinStudio and packages for it, I can build and debug normally. After release and signing I am not abble install apk on other phone than my own phone. Instalation on other phones stop working with App not installed. This app isn't compatible with your phone. Phones has Anroid version 4.3 or 4.2.2. Older version Xamarin making installable apk normally. What is else, now?????