Originally featured back in July, as a refugee from iOS and Android, Guitar Tuna immediately impressed as being slick and accurate, whatever your instrument. Well, it's back and completely overhauled in a new v3.0, with the full changelog quoted below.
A free download and for basic tuning and metronome, if you were to go for every tuning and every chord pack (i.e. the 'All' purchases), you'd be out about £10. Expensive as mobile apps go in 2014, but Guitar Tuna really is incredibly slick, so quite possibly this will be worth it!
And here's what's new for v3.0:
Pro-accuracy feature (choose in Settings)
Faster Audio recognition
Violin, Viola, Cello, Fiddle tunings
Electric guitar headstock (and other instruments)
Switch note-name convention
Being a guitarist myself, I had a quick whirl through Guitar Tuna's overhauled interface:
The range of possibilities is impressive, with the slight caveat that anything beyond a standard tuned guitar is a small freemium purchase; (right) the new Settings panel, note the headstock option and the new 'Pro-accuracy' toggle...
A big deal is made of the 'Cent'-level tuning accuracy, though in my experience Guitar Tuna was pretty accurate in real time in either mode. Note also the alternate headstock shown here.
The chord library presentation and UI is top notch and very slick; (right) the top in-app purchase gets you everything, I believe. £7.49 isn't too expensive for a quality musical aid, given the other costs in the trade.
Also included are mini-games, to help you memorise chords; (right) tuning packages for every instrument are available, but included in the various in-app-purchases.
The freemium model seems odd at first in a (fairly) serious application, but it works well - casual guitarists can tune for free, more serious players spend a little and the pro instrumentalist gets to spend the price of a couple of cups of coffee, etc.