Most of us are happy to just use one smartphone for livestreaming. In certain cases, it makes sense to use multiple devices to capture video for two different platforms. The Octo Mount Dual iPhone Holder can help. It has a universal clamp that can handle 1 or two phones.
You can use this to capture better selfies or stabilize your video. It has a rubber handle that gives you a solid grip. You also get a wrist strap to keep hold of your phones. This dual iPhone holder supports horizontal and vertical recording.[where to get it]