Here is how to stream the contents of your Android smartphones/tablets to a PCAllCast:Mirror Beta:ChromeCast:

AllCast:

AllCast lets any Android device send photos and videos to the Chrome desktop browser for a while, but mirroring your screen has been a pain; if you don’t have a Nexus 5, you were out of luck. Koushik Dutta has reworked the app’s mirroring code so that it now uses a common video format (H.264), letting you mirror the screen of any halfway modern phone on your PC; if you can run AllCast in the first place, you’re probably fine. There’s significant lag, but it should be enough to show your friends a hot new app without having to buy a Chromecast (or a TV, for that matter). The upgrade should arrive soon, so swing by Google Play if you’d like to use your computer as a second screen.

Mirror Beta:

Mirror Beta is an app by Koushik Dutta, the creator of ClockworkMod recovery and the AllCast app. The app is still in beta and if you’re using KitKat you’ll need root access for the app to work. On Lollipop root is not needed. On your PC/Mac, download the AllCast Receiver app for Chrome and launch it. On your Android phone open the Mirror Beta app and make sure both devices are on the same Wi-Fi network. The Chrome app will show up on screen. Tap it to start mirroring. In a couple of seconds the Android screen will show up in the AllCast Receiver window. You’ll see that there’s a watermark in the bottom-right corner. Right now the app is free and in beta. There doesn’t seem to be a way to remove that watermark.

ChromeCast:

Chromecast is a $35 HDMI dongle that you can attach to a TV (or a monitor) to turn it into a media receiver and player when connected to Wi-Fi. Android phones running KitKat 4.4.2 and above are able to mirror (cast) their Android phones to screens connected to Chromecast. Of course, this feature is in beta as well and the feature is only optimized for Nexus devices. I got a warning about this during setup but I didn’t encounter major performance issues. If you’re on Lollipop you’ll get better results. To get started, download the Chromecast app and connect to your local Chromecast. Tap the menu button and select Cast screen. Bypass the warning, choose your Chromecast and your Android screen will be visible on your big screen TV. You can do anything here. Switch to landscape mode, play YouTube videos.