You will need to stream them on Chrome tab from a PC or Mac. You will need a fairly new computer to be fast enough to stream without lag, and the computer will have to remain on the streaming during the whole time. It would not be like YouTube or Netflix app where you just use the device for control. The computer actually has to do the heavy lifting to download the video from internet, display it on the computer and stream it wifi direct to your chromecast. My new Dell Venue 8 Pro tablet could actually do it though.. and that' s what I use to watch videos on Putlocker and sites like ABC, NBC, CBS, CW, etc... The only sites that don't work are the ones that uses Silverlight like Amazon Prime Video. If you stream a video using Silverlight, it will play fine on the computer but showing a blackbox on the TV.