Droidcam Client - DroidCam turns your Android device into a wireless webcam, letting you chat on Skype, Google+, and other programs. It also works with OBS/XSplit/etc for streaming to Twitch.
You can also use DroidCam as an IP webcam (or Surveillance Camera) via a Internet browser virtually on all networks. Use it as a simple pet cam, spy cam, or a security camera.