This app was mentioned in 4 comments, with an average of 2.25 upvotes
If you don't mind using Apple's AirPlay protocol, I've always found AirBubble to be pretty solid for this kind of thing.
You can try airbubble or airplay receiver in the playstore and see if they work for you.
Sure. An app like this:
https://play.google.com/store/apps/details?id=com.bubblesoft.android.airbubble
Turns your Android into an Airplay receiver. Then from the Chromecast app on your Android phone you cast the system audio to your multi-room group. Then airplay from IOS to the Android device and it plays through the multi-room setup.
you can download an app to turn your android into either a dlna receiver or an airplay receiver and stream audio via wifi. the only issue is that the audio tends to have a little bit of lag to it, so its fine for music streaming, not so good as a wireless speaker solution for video/movies.
https://play.google.com/store/apps/details?id=com.bubblesoft.android.airbubble&hl=en
https://play.google.com/store/apps/details?id=com.waxrain.airplayer