How to set size of desktop app migrated from mobile app?

We have a SQLite based flex mobile app(for iPads), which users would like to have on their desktops and surface pro devices(for ex: Dell XPS which runs on Windows 8, touch screen). Hence I created a flex desktop application project and released a native installer (.exe) which can be installed as an application. Application works as expected, but only problem is the display.

By default, the device has screenDPI of 72 and hence application takes 120 as it's default applicationDPI.

This is how it looks with default 120(without assigning applicationDPI value):
http://pasteboard.co/aSSrDdXtp.png
It covers entire screen, but its too big overall.

I changed the applicationDPI to 240 and now it shows up as expected (smaller\scaled down components), but it doesn't cover the entire screen, even though the application has the width and height set to 100%. Screenshot:
http://pasteboard.co/15urH7AHf.png

I have no idea why it's not covering entire screen. Has it got to do anything with applicationDPI? Kindly let me know if there is something I can try to make it cover entire screen.

I have attached sample fxp project.

I have also uploaded the test fxp project in google drive:

https://drive.google.com/file/d/0B82pGRq1xr11bXV4V0dLdnR0aXM/view?pref=2&pli=1

, which has login page of the actual application (project's lib folder includes required mobile.swc and mobilecomponents.swc too).