This is the professional version of DaTuner Chromatic Tuner, reviewed recently on Android Central:"For the Android-loving musician, I think DaTuner Pro is easily the best tuner you can have on your device. I used to give that title to *see review!*, but DaTuner has proven to be so powerful, easy to use, and accurate, it'd be foolish to not use it."http://www.androidcentral.com/android-app-review-tuner-datuner-proDaTuner is an all-purpose chromatic tuner with a simple interface. DaTuner converts the fundamental frequency to the nearest note and error in cents for quick and easy tuning of your guitar, ukelele, violin, bass, cello, mandolin, piano, harp, saxophone, balafone, Ducati timing belt, harmonica, kazoo, you name it.1.) No dead zone - screen changes to green when tuning is good.2.) Auto-Sensitivity - no configuration required.3.) Bright, easy-to-read display.4.) Quick, accurate and precise. < 0.3 cents @ E3 (329.62Hz), <0.1 cents @ C5(1046.5Hz), < 1 cent @ A2 (110Hz)5.) Screen lock: Lock to the note you want to tune, even if extremely out of tune and make your way up/down to it.6.) Filter lock: Lock and filter to a specific note and filter out everything outside that note's range.7.) Ad-free!8.) Reference frequency adjustment for orchestra tuning.9.) Choice of colours for sharp/flat10.) Transposition.11.) Temperaments. You can modify the ones that exist or add your own using a text editor. The temperaments are saved on your external memory under the /DaTuner directory.12.) Notation (ie Solfége, English, English sharp, English flat, Northern European.) Customization of these will be possible in a future upgrade.13.) Emulated strobe tuner display14.) Digital display of error in cents15.) Pitch pipe (triangle, sine, sawtooth, square)16.) Pitch pipe auto mode (no touch!)17.) Accelerated tuning algorithm.18.) Sample rate range 8kHz - 48kHz.DaTuner's display is easy to read; nearest note and octave is displayed in a giant, easy to read font in the center of the screen, and frequency in hertz plus error in cents is displayed at the bottom of the screen. Sensitivity is auto-adjusted, but can also be adjusted by touch via a bar on the left-hand side of the screen, and the speed/accuracy of the algorithm and the relative frequency (if other than 440Hz) can be adjusted via the configuration menu.There is no "dead zone" with this tuner app as is the case with many other apps. Instead, the whole display turns green when the incoming frequency is within a configurable range of the target frequency and you can still see small changes in pitch even within the "in-range" area. Both the "in-tune" range and the colours shown for sharp and flat can be configured in this version. The emulated strobe tuner display provides additional visual feedback to how close to the desired note you are. Screen lock and filter lock allow you to select the note that you would like to tune to, with filter lock ignoring anything outside of the range of the note you wish to tune, which is useful for tuning in noisy environs.I have tried my best to eliminate bugs from this software, and I apologize in advance for any problems you might find. Getting feedback via email, negative and positive, is very appreciated, so please email me all of the problems that occur so I can fix them! Try out the free version of DaTuner first to be sure that you want to buy the "pro" version.BUGS:- Doesn't detect any notesTurn on mic auto-adjust! Ensure that the signal rises above the little yellow triangle - the algorithm doesn't run until this level is exceeded! If using auto-adjust, stop playing for a moment occasionally to allow the auto-adjust to re-sample the background noise.