insTuner - Chromatic Tuner (iOS) app for FREE

InsTuner is a chromatic instrument tuner that can helps you quickly and accurately tune your instruments with your iOS devises. With advanced DSP(digital signal processing) algorithm, it is highly accurate(±1/1000 semitone or ±0.1 cent precise). Rather than providing only one display mode like other tuners, InsTuner supports customized tuning display mode, such as Instant Tuning Display, Fine Tuning Display, FFT Display etc. What's more, many advanced customized features are also supported, such as Concert A calibration, historical temperaments and transpositions, which make it more powerful than other tuners.++