A quick heads up for those of you who rock the Ricoh Theta S (and the original Theta) for your 360-degree photography needs — the corresponding apps now will display pictures and videos for "head-mounted displays." That can mean a lot of things (and nothing at all), but the short version is that you can now view your stuff in Google Cardboard.
The app(s) gives you the option to view in a standard screen, or two modes of VR view. There's single lens, and double lens. (Most of you will want the latter.)
The Theta apps aren't exactly great for viewing images in 360 degrees (they work fine, but they're clunky), but this eliminates the need to upload somewhere else just to view in cardboard.