The sound of your smartphone may not be much, but have you wondered what it would be like to have all the smartphones of all the friends at your house playing the same music at the same time? That's precisely what you can do with AmpMe - and it now even works with Bluetooth speakers.
The app AmpMe is free and available for Android and iOS, and once you tell your friends to install it it allows the host to use all the devices in range to play the same music in perfect sync.
You can choose songs from SoundCloud, YouTube, or your own personal library; and instead of having dozens of people trying to hit the play button at the exact same time, you can relax and let the app take care of that for you. Instead of the cacophony that would ensue, you get a perfectly orchestrated symphony of synchronized music that everyone will love.
The latest version of the app allows you to use bluetooth speakers (sadly just one for each smartphone) and also allows you to do some fine tuning should you need to adjust the delay on a specific device in order to get it in perfect sync.