You need a mobile license in order to download/customize the iPhone and Android apps. If you have them, then in order to remove the 'Add Site' and lock it to your own, then you need to:
Changes in the Classes/config.h file:
To lock the app to your site only, look for the following code
// specify site you want to lock to, for example: #define BX_LOCK_APP @"mysite.com/dolphin"
#define BX_LOCK_APP nil
You can change it look something like this
// specify site you want to lock to, for example: #define BX_LOCK_APP @"mysite.com/dolphin"
#define BX_LOCK_APP @"www.mysite.com" (I had to use the www in front for it to work)
- Colors can be changed here too