Consisting of three well-made pieces, the Guitar Sidekick from Castiv does one thing and does it well: holds an iPhone or iPod Touch at the top of the neck of a guitar (or other similarly sized stringed instrument) for easy access to the iOS device.
The metal portion of the clip attaches under the strings just above the guitar neck itself, and locks closed with a plastic sleeve that fits around both halves of the metal clip. An adjustable, rotating clamp screws securely to that plastic sleeve, allowing a free rotation and easy position for the iPhone or iPod Touch attached. The clamp is padded, and can be easily resized via an internal spring to accomodate a wide range of cases, as well.
Once attached, an iPhone or iPod Touch can be safely used from the neck of a guitar, allowing any of a number of music apps to be used while playing the guitar, from tuners to chord and tablature charts. Players can play along to video lessons or other rich media that plays on their iPhone or iPod Touch. I personally connected the Sidekick to my acoustic and electric guitars, as well as one of my larger tenor ukuleles. It felt solid, secure, and was useful when using my tuning app as well as some lyric/chord charts that I'm still working on memorizing.
The only potential issue is the eventual wear and tear on such a device - will the plastic parts hold up as well as the metal? Only time will tell, but until then, this is a worthwhile purchase for any musician (or uke player!) who needs an easy way to connect their iOS device to their guitar.