There are actually quite a few tuners in the AppStore (mostly aimed at guitars) but Clearview caught my eye mainly because of the many features is offers and the fact it can tune “acoustic or electric guitar, bass, bowed strings, woodwinds, brass, piano and any other instrument that can sustain a tone”. It also has support for custom temperaments (as well as pre-set temperaments), transposition, digital pitch pipes and a handful of other features. Now, I don’t play violin or piano but an app that can tune such a range of instruments must have something going for it, especially at £2.39.

The main screen layout from top to bottom shows the current temperament (default is Equal Temperament), the ± 25cent fine tuning display, the tuner or pitch-pipes buttons, the tuning wheel and the settings (‘i’). The default settings are the ‘standard’ for guitars (and presumably other instruments) of a middle A at 440.0Hz, a transposition of C and equal temperament. If you’re not familiar with temperaments they are very slightly different tunings to give a subtle (or not so subtle) change of sound to the instrument – Cleartune comes with 23 pre-set temperaments as well as the ability to add your own custom ones.

Cleartune is simple to use; to tune your instrument make sure the tuning fork is green and the power button in the middle is also green and then simply play your note. The tuning wheel will give you a quick indication of the current note and then you use the top bar to fine-tune it. As the app detects the sound the yellow triangular marker on the tuning wheel becomes more opaque and then turns green as it reaches the correct tuning. You can also press the padlock at the centre of the tuning wheel and then rotate the wheel to choose a specific note if you wish.

I’ve not used pitch pipes for years, personally I hate them but I presume by the inclusion of digital pitch pipes in Cleartune that they are still used for tuning certain instruments. You are given a range of 10 octaves from 27.5Hz right up to 14,080.0Hz. The iPhone’s internal speaker does seem to struggle though on the ridiculously high and low ends of this scale using the Sine wave however there are other options for Triangle, Sawtooth and Square that make the waveform more audible. Realistically though you would never need such high or low notes although 12,500Hz seemed to send my cat scatty! In pitch pipes mode the lock on the tuning wheel forces the note to a full tone (e.g. E, F#, G) but unlocked it allows any point in between in 0.1Hz intervals.

The other features not already mentioned are the ability to calibrate the Middle A (A4) in 0.1Hz intervals (standard is 440.0Hz), various different (and custom) notations for the tuning wheel (A, Bb, B / A, A#, B / Do, Re, Me etc), transposition (e.g. for Bb instruments), temperaments (already mentioned) and needle dampening (basically adjusts the sensitivity).

One feature I liked that I did not see mentioned on either the website or in the AppStore was the very simple use of the iPhones accelerometers. Turn the iPhone upside down and the display turns around for you – this is particularly handy when you are using an amplifier as the iPhone’s microphone is then at the top in just the right position to pick up the sound from the speaker. As a side note, you will need an external microphone if using Cleartune on a 2G iPod Touch.

Cleartune is packed full of advanced features but is suitable for both basic users as well as more advanced users. For a mere £2.39 you get far more than you ever could from your basic ‘stomp-box tuner’ at around ten times the price and probably from many rack-mounted tuners at one hundred times the price. Tuning my guitar using Cleartune and then playing it back through my other tuners confirms that the tunings are accurate. It would be interesting to tune a guitar using Cleartune and then see how it compares to a pro rack-mount but that, perhaps, is one for another day!