Both apps are written by third parties and use publicly available APIs to interact with and download content from their respective parent sites. Both apps provide an easy to use interface for browsing and searching through collections (mixes) and then playing back the listed tracks.
If you're an existing user of one of the parent sites, or are looking for an alternative source of (free) music to listen to you on your Windows Phone device, then either app is worth a look. Alternatives include 8tracks (another third party client), AUPEO Radio (which we wrote about here), TuneIn Radio, and Grooveshark (plus many more in the Marketplace).
Mixtapes
Mixtapes is a well established Windows Phone app, which was first released in September of last year, but has since been updated multiple times. It's the more mature of the two apps, and is powered by the better known 8tracks service (500,000+ mixes available).
The recent version 3.0 update added the ability to pin multimixes (list of mixes) to your Start Screen, improved the WiFi connection managements, and added YouTube integration. Other notable features include deep links into Zune Marketplace (for buying music), Live Tile support (show currently playing mix), the ability to share the mixes you are listening to on social networks, and the ability to filter listings by your own custom tags.
Markeplace description:
Mixtapes gives you free access to millions of songs organized into mixes by listeners like you. Start listening to great music right away or create an account to track your favorite mixes, songs, and DJs. Stop letting marketing dweebs and computer algorithms pick your music and hear what real people from around the world are listening to. Powered by 8tracks.
The Mixtapes app can be downloaded from the Windows Phone Marketplace for free.
Mixtapes Cloud
Mixtapes Cloud is the new app in town, having only released last week. The parent site, livemixtapes.com, isn't as well known as 8tracks, but still boasts thousands of mix tapes to listen too, and has an emphasis on curation by Djs (the site's tag line is "your favorite Dj's favorite website").
A similar feature set to Mixtapes is available (search and browse for mix tapes, support for shuffle and repeat play, playing history and more), although the app is not so slickly put together. However, one feature in particular caught our eye, the ability to cache tracks for offline listening. That's a very handy feature if you spend anytime in places without a decent 3G or WiFi data connection.
Marketplace description:
You are able to listen and cache thousands of free mixtapes by Mixtapes Cloud. And you don’t need to register any accounts.
There are two version of the Mixtapes Cloud app; a free ad-supported version, and an ad-free commericial version (£0.99 / $1.29 / €1.29).