Django project - serve one of the apps on different domain
You could run each each domain site independently using their own settings. 
This way you can control how much they share using the same codebase.

Create separate settings for both sites. Where each of the settings specify a different ROOT_URLCONF and any extra setting required such as ALLOWED_HOSTS.
Create two separate URL files for each site so you can specify exactly what URLs you want to make available for that given domain, make sure this is specified in each ROOT_URLCONF setting.
Run each site as a separate instance using the settings you have already created. Example using the development server.
python manage.py --settings package.settings.site_a
I have django project with consist of multiple apps. 
One app contains all core functions and code (common models etc). I serve it on one domain.
Now I want to add new app which will use some of the other app's models BUT all URLS of this app should be served on different domain.
Is it possible?