Spotify Connect is great! Since some days ago we can control the Desktop App from our mobile phone or tablet, including volume control. What's still missing is volume control from Android to Android.
In this thread it is stated that this function already works, but I have several Android devices at home, and on none of these devices does volume control with Spotify Connect work. More people have this problem, see this thread. It does work from Android to PC, which is already great.
I've contacted Spotify Support, and they confirmed that volume control from mobile to mobile doesn't work at the moment.
So, the idea is:
Please implement volume control with Spotify Connect from Android to Android!
Hey folks, as this idea has reached 100 kudos we've chased an update for you all. At the moment we're marking this as 'Not Right Now' since controlling volume from Android to Android with Spotify Connect isn't currently in our pipeline. However, if this changes we will of course let you know here, thanks!