It looks like index.html cannot be overridden per app, only per site. From the above link:
" Not every template in contrib/admin/templates/admin may be overridden per app or per model. The following can: - app_index.html - change_form.html - change_list.html - delete_confirmation.html - object_history.html " -- You received this message because you are subscribed to the Google Groups "Django users" group. To view this discussion on the web visit https://groups.google.com/d/msg/django-users/-/qvVsOP6j5JsJ. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
