I also tried to add a Script Editor Webpart but was also unsuccessful.
I have read about creating a visual webpart in VS2012/VS2013 to add Backbone to a page but our network engineer has not been able to correctly configure our site collection for VS app development so I am trying to find a workaround solution so that I can meet my deadline even if he fails to meet his.
The Visual Studio issue is that when I press F5 to test the build, the build completes properly but I am presented with a credential dialog that will not allow ANYONE to log in through. I am a site collection admin and site admin on the site collection and I still get access denied after the build and our network guy can't solve this.
Thanks in advance.