I have a music app on my phone. I want to listen to it through nicer speakers than the phone's built-in speakerphone. If I had an iPhone, I'd either use a speaker dock (which both charges the phone and receives music through one port on the bottom of the phone), or I'd use AirPlay.
Neither of these options seem to be available for Android devices. So, what are the alternatives? Note, this is NOT a request for recommendations of specific products, but a list of available options.