As an iPod owner I don't use my phone as a main device. RIM's media application is ever so slightly basic compared to Palm's offerings of Real Player or pTunes.
Back on my Treo my MP3 player of choice is Busker from Electric Pocket. Why?
Well I covered that in a review a while ago, but mainly because I love cover art (The main reason I own an iPod Touch is coverflow!). Now Flipside got me very excited, it's not a port of Busker; it's a brand new player from Electric Pocket.
Flipside had been long awaited by the Blackberry community, there isn't much competition in the area so when a strong developer comes along to make an MP3 player that has a gorgeous interface with cover art browsing it was bound to be talked about.
Interface wise FlipSide allows you to flip through your cover art to choose album, add to play list, or just to play an individual song. This is incredibly effective using the scroll ball found on the Curve and Pearl devices as a quick flick sends your cover art whizzing by. The interface really is where Flipside excels, unlike most Blackberry applications which can be a tad bland.
On the cover art side of things one very cool feature brought over from Busker is the ability to download new cover art as needed, very handy (if slightly slow over GPRS)!
As expect Flipside works perfectly playing in the background and can be flipped to from a shortcut it creates in the application menu, simple and effective.
I can't really pass judgement on the audio quality as I have no baseline comparison (and a tone deaf!), but it's as good or better than Busker is on my Treo, I suspect this will vary between Blackberry devices though.
So if you want a good looking, good quality player for your Blackberry Flipside is a superb choice. Go and have a nose over at the site here.