I'm trying to add a video to my Photos app in the simulator. I've been using the Safari trick (How do I add images to the iOS Simulator) for a long time but doesn't work for me with the iOS7.1 simulator.
When I drag from the Finder I get the green + sign but the video doesn't play in Safari so I can't save it to Camera Roll.
It works fine for the iOS8 simulator with Xcode6.
Per your request to copy my above comment into an answer...
You should be able to do this by dragging the video into your application's folder, and then inserting it programmatically. See this post.
Glad that worked for you! Obviously, make sure that's not in any production code.