According to this page - https://www.spotify.com/us/chromecast/
Spotify users should be able to cast music from native Spotify mobile app (iOS), but I don't see my Chromecast pop up on my available device list. I only see my AirPlay available. I tried on both iPad and iPhone, also tried reboot iPhone and Chromecast, still don't work. Could someone help me with this issue?
Solved! Go to Solution.
For people with the first generation Chromecast, the firmware update is now rolling out. Try restarting your Chromecast to get Spotify support.