Drupal as an application development framework
50% to 90% of application development effort is unrelated to the work you want your application to perform. Drupal and some add-on modules can replace the wasted effort, freeing you to focus on the bit you need.
A few minutes invested on installing the Drupal infrastructure on a desktop computer gives you the base for any type of application. You can then expand the application to the Web or hand out copies to all your staff.
Want portability? You can already run PHP on Android. Drupal is next. There is no technical limitation to where you can run Drupal based applications.