I first heard of this a good while ago and seeing as I've now fully but ever so reluctantly converted to file format music (After wearing out my last and final CD Player) I thought I'd try it out. Any old smartphone, above Android 4, or thereabouts, if you want gapless, but that's the only requirement for compatibility. All that's required is the phone and a music player app of your choice. Great freebies are Blackplayer, Pulsar and Foldplay. These are all free and support gapless playback and flac. So once installed, link it to any Bluetooth Speaker of your choice and away you go. I would add that I have a selection of dedicated DAP players that boast gapless playback, but I've found this feature to be a bit picky with some albums on these players. The advantage of using an old smartphone is that you get to choose your music player via an app and you also get full gapless with no playback issues. Smartphones have a lot of power with regards to RAM so you can expect great performance. Also worth mentioning is the fact that this is a great way of getting the most mileage out of something that you've paid a lot of money for. I upgrade my phone every 2 to 3 years (like most probably do), so if I can then squeeze the remaining life out of it as a media player then that's brilliant. Also a great saving as Sony media players are based on the Android system, with a few tweeks, so basically your paying a lot of money for something that's really very similar to a mobile phone. My friend paid nearly £500 for a Sony DAP, when we compared the performance neither of us could really hear a difference...well not anything that was blatantly obvious. If you're on a budget and want a media player then give it a go......anyone else got any thoughts on this ?