The login page that is embedded into a Lianja PhoneGap App for phones and tablets can be customized and branded,

The default page for a phone is in c:\lianja\library\mobilelogin\login_phone.html
and
The default page for a tablet is in c:\lianja\library\mobilelogin\login_phone.html

If these files exist in the app directory then they are used instead, so just copy the required file into the app directory and customize it.