Before anyone asks about customizing the login page for mobile Apps you can customize it yourself.

The default HTML for the login page that is embedded into a mobile App that requires authentication can be found at:

c:\library\mobilelogin\login_phone.html
and
c:\library\mobilelogin\login_tablet.html

If login_phone.html (phones) or login_tablet.html (tablets) exists in the App being built then this will be used rather than the default login page. Look at the defaults to see how authentication is achieved.