Review: Samsung Sidekick 4G
The Sidekick 4G doesn't have a "music player" application that I could find. Instead, it has a "Media Room," wherein users will find their music, movies, and TV shows. The user interface of the Media Room is generally easy to figure out and use, and it ties in other services such as Slacker Radio. Finding all your content in one spot has its benefits, but I prefer the bare-bones functionality of the stock Android Music Player to the Media Room's controls.
Alternately, you can use the Amazon MP3 software that is installed. The latest version of the Amazon MP3 software now allows for playback of local files, as well as the Amazon Cloud Service and Amazon MP3 Download Store. This little app has grown up a whole lot.
Slacker is already on board, but of course you're free to go to the Android Market and download any music-related software that you wish.
The Sidekick 4G ships with Samsung's Media Hub on board. The Media Hub is Samsung's own content store. On the Sidekick 4G, it offers movies and TV shows for rental or for purchase. You have to set up an account in order to do so, and movies can be billed to your T-Mobile account.
The T-Mobile TV application is also present, as is YouTube. The Media Room pulls content from these three sources — as well as videos shot by the Sidekick 4G itself — and makes them available in one spot. I have to admit, that's kind of convenient.