chromecast has supported screen mirror for months. https://support.google.com/chromecast/answer/6059461 but strangely, the mirror to my Nexus 4 (720p screen) was very smooth, but the mirror to my Nexus 5 (1080p screen) was very very slow. haven't tried lately.
【在 F********y 的大作中提到】 : one more vote : 我比较过拖线和Chromecast(虽然不是airplay但是原理差不多),拖线的太累,操作 : 也很不方便。 : 如果看的内容基本局限在可以Chromecast的那几个app,完全可以考虑入Chromecast