CanSeeVoice app for iPhone and iPad

This application shows the frequency of your voice.
When you hit the piano keyboard, you will hear the sound of the keyboard, so you can check the height of your voice.
Be careful with the volume when using headphones.
This application has the following features.
A) Display of the value of a fundamental frequency
B) Display of the amplitude level of the wave/FFT graph
C) Button of Recording/Stop
D) Button of PlayBack/Reverse PlayBack
E) Button to change graph
F) Slider to change system volume
G) Button of noise rejection
H) Display of a fundamental frequency on the piano keyboards & output sound
I ) Display of all wave data
J) Display of the wave graph
K) Display of the FFT graph
L) Display of relationship between FFT and time