Gnomecast is described as 'Chromecast local files from Linux - supports MKV, subtitles and 4K!' and is an app in the Video & Movies category. There are seven alternatives to Gnomecast for a variety of platforms, including Mac, Windows, iPhone, Chromecast and Xbox. The best alternative is Airflow. It's not free, so if you're looking for a free alternative, you could try AirPlay or Videostream. Other great apps like Gnomecast are AirServer (Paid), AirParrot (Paid), MiracleCast (Free, Open Source) and MKMirror (Free).
AirPlay lets you stream music throughout your entire house — wirelessly. AirPlay wireless technology will be fully integrated into speaker docks, AV receivers, and stereo systems from companies such as Bowers & Wilkins and Denon.
Select any video from the Videostream extension for Google Chrome and, using the Chromecast extension, play it on your Chromecast. It's fast and simple to use. Videostream supports subtitles, MKV, AVI, MP4, playlists, and more.
The MiracleCast project provides software to connect external monitors to your system via Wi-Fi. It is compatible to the Wifi-Display specification also known as Miracast. MiracleCast implements the Display-Source as well as Display-Sink side.
MKMirror allows you to mirror your Desktop, built-in Camera, video and audio devices to Smart TVs and mobile devices. MKMirror uses HTTP Live Streaming (HLS) protocol, an adaptive bitrate streaming communications developed by Apple Inc.