Ever wanted to send a song to your roommate and have them listen in real time along with you? AirPlay doesn't support iOS-to-iOS device streaming, so you will have to turn to a third-party app like Seedio to simultaneously play a song on multiple devices. It's a slick experience with one song, multiple devices and an exponentially loud beat.
Most of the power of Seedio is hidden underneath a no-frills UI that's easy to use. When it launches for the first time, each button on the screen has a label that tells you its function. There are not that many on-screen elements -- one to add music to a playlist, one to set up a device as a broadcaster or receiver, one to share information about Seedio with friends, one to access a tutorial and one over-sized play button to get the music flowing.
Using the app is exceptionally easy. Create a playlist from your iTunes library or add them from external sources like SoundCloud or a streaming URL. The option to pull music from an external source requires an in-app purchase. Once the music is selected, just set one device as a broadcaster and the other devices as receivers. The receiver devices will search for the broadcaster and connect to it with just a single tap. The person with the broadcasting device just has to hit play and the audio will be pumped to all connected devices as the same time. It literally takes just a few minutes to configure and connect all the devices.
There is one caveat that could disrupt your mobile music party -- all the devices need to be on the same WiFi network. There is a workaround if you have a phone with a WiFi hotspot functionality, though. You can create your own WiFi network by turning on your iPhone's personal hotspot feature. You then can use that mobile WiFi network to connect all the devices together so they can share the beat.
Seedio is perfect for people who want to fill a room with sound using only their iPhones. It's also useful for sharing some tunes with nearby people. I've used it to send songs to my husband when he's downstairs and I'm on the main floor of our house. Seedio is normally US$2.99, but the app is free for a short time. At that price, you can't go wrong.