There are quite a handful of gadgets available for automatically tuning your guitar. The Roadie Tuner offers the same, all while adding a few useful functions that make it easier to maintain your instrument's health.
Instead of a standalone tuner, the device pairs with a smartphone, using your handset's processing abilities to perform precise calculations that help ensure more accurate tuning. Aside from that, the app allows for more comprehensive evaluation of your guitar's tone quality, recommending that you replace your strings once it detects notable deterioration.
The Roadie Tuner uses a Bluetooth-packing palm-sized device that attaches onto a guitar peg and winds it automatically based on commands received from the app as you pluck on the strings. The app is designed to learn your instrument and adapt to it, allowing it to tune your guitar quicker and more precise the more it's used. It's smart enough to know when you're plucking the wrong string, too, so you can expect accurate tuning even if you're the sloppiest guitar player in the world who, incidentally, also just had a few drinks.
When you're tuning an electric guitar, they supply an adapter for hooking it up to your phone, but the app itself will delete environmental noises if you need to tune your acoustic six-string instead. Need alternate tunings? Not a problem -- just specify it in the app and the device will work accordingly. Even better, it can work with any string instrument that has a standard guitar peg, so bass, 12-stringers and similar rigs are all fair game.
Roadie Tuner is currently a fully-funded Kickstarter project. You can still reserve yourself a unit for the upcoming run, with pledges starting at $79.