I am new to Android development and I am trying to use the Android's Cast API. To start I have cloned and used the CastHelloText demo app. But there should be a cast button in the ActionBar/ToolBar which is for some reason not visible. I haven't registered any app to Cast Developer Console, I am just using the project as is, which means I am using the app id mentioned in their project. Does the chromecast device need to be powered on and plugged in and the android phone with the app be near/in front of the tv in order to make the button visible? I am a little confused as there is nothing mentioned anything like this in the documentation.
Your chromecast device should be powered on and on the same network as your phone (same wifi network on both). You do't need to be in front/near the TV as long as both devices are on the same wifi network but I presume you do want to be able to see the TV's screen to see if your app works or not, don't you?