As a "practice" device on-the-go, this is very interesting. It reminds me of the Martin Backpacker. It's meant to be compact for easy travel. But it hooks up to an iPhone or iPad (or Mac) wirelessly. No lugging a guitar, no cables or amps, and not only can you use it with Garage Band, but it appears that you can use it with a practicing app like AnyTune Pro+ (!!!). An initially high $299 as an MSRP I can maybe understand. But it may be worth up to $199 if it's of decent quality and lives up to it's intentions/potential.
Looks like no tuning would be required since the strings are only used to provide data to the sensors.