There has been speculation for some time that Amazon was preparing to build on its Kindle Fire tablet business by launching a smartphone, pitching it into even more direct competition with Apple and Samsung (and Google). We may finally get to see the product later this month: journalists in the US have been invited to a mystery “launch event” on 18 June by Amazon, complete with a teaser video showing people looking down and saying things like “It moved with me!”. Quiet at the back, there. Engadget suggests that the smartphone’s key feature will be its use of five front-facing camera to track facial movements for some kind of whizzy 3D interface. We’d expect music to be part of the device too – Amazon’s own MP3 store obviously (and perhaps its equally long-rumoured streaming service as part of its Prime subscription), but also potentially partnerships with third parties. Bloom.fm, for example, claimed to be in talks with Amazon over a mystery device partnership in documents sent to potential buyers in May – that clearly won’t happen now as the service has shut down, but it suggests Amazon isn’t planning to do everything itself, music-wise.