the author of this app says:
This is an advanced tuner for musical instrument tuning and vocal practice. It can detect off-tuned notes in recordings and uninterrupted performance. It can also alerts when your piano needs tuning.
It indicates the playing note on the Mathematical Cochlea with a big dot and needle for you to see clearly whether it matches the target tone. The singing mode automatically shows singing in the chromatic scale from C2 to C8, and users can define target tones for up to 6 strings from C3 to C6 in Custom mode.
- PocketPC 2002