If you have a hard time tuning your guitars - even 12-string units, check out the Roadie 2. It's pretty awesome! There is a lot of cool tech behind this unit.
The Roadie Tuner is one of those feel-good Kickstarter success stories that makes the whole experiment worth it. It's a quirky solution to a common problem, and it actually shipped to its backers! The tuner works by pairing with a smartphone to listen to the string you're plucking, and then robotically rotating your instrument's tuning peg until the string is in tune. Source: TheVerge Click here to read this article!