Panoramic Guitar Suite is a very straight-forward app that a potentially invaluable tool for guitarists (or players of a few other stringed instruments). The program includes a metronome, tuner, and chord library. Several options are available for these features, including a tap-to-set metronome with different sounds, languages, and even different background images for the simulated fretboard.

S2P (Slide To Play) is a stylus-free MP3/WMA player application, in the form factor of S2Unlock (from the same dev at XDA-DEV)

Fully operable with your fingers, displaying a big hight quality image of the album (regular form MS), you can listen to your playlist even in random order, and make a horizontal gesture to listen to the next/previous one.
The folder to scan is configurable, too (no WAV files from programs, for instance).

Need more effect ? Slide verticaly, and you'll see all your albums in a caroussel mode... Yummy !

Just one thing to mention : You'll need to edit the registry to change default value for sreen-off (default is 25 sec)... But it's a very little problem...

GSoudBox is an application for HTC Windows Mobile phones with G-Sensor. It plays a wide variety of sounds. The sounds are triggered by shaking the phone using a variety of gestures.

Features
1) Wide variety of instrument sounds
2) Adjust the sensitivity of the G-Sensor
3) Touch optimized interface
4) Animated graphics
5) and much more!

Online TVx is a simple windows phone app that allows you to watch online TV streams on your device. Sports, Movies, Music and a lot more categories to choose from. Read to check out our impression about the app.

Play the piano on your phone.

Music player for windows phones.

Control Windows Media Center using your Windows Mobile phone!

Control Windows Media Center using your Windows Mobile phone!

A light-weight application that provides access to BBC iPlayer, Hulu, Five On Demand, MSN Video and SBS directly, eliminating the requirement of a (flash-enabled) mobile browser.

FM radio player with RDS decoding for VGA and WVGA devices.