Playing an mp3 (from my phone) through my internet radio
AllShare is a Samsung specific product, which might not be available to devices of different brands. However, as it's basically a DLNA server/client app, you might want to take a look at some of the many alternatives available. A very good choice would be BubbleUPnP, which acts both as server and client (so you can stream from your device to other DLNA/UPnP clients as well as the other way around):


  BubbleUPnP is a full featured UPnP/DLNA Control Point, UPnP Media Renderer and UPnP Media Server. Play easily your music, videos and images on your phone and devices on your network (DLNA TVs, XBMC, WMP, ...), from your external UPnP Media Servers. Play your phone/tablet media to those devices.
  Browse and play your local phone/tablet and cloud media from other devices (PS3, ...).
  
  BubbleUPnP can also be used as a standalone music player, even without any network connection.