System requirements?

Compatible with iPhone and iPod Touch. iPod Touch requires an external microphone.

In which countries Pitch Primer is currently available?

Pitch Primer is available worldwide except for China.

When will you release Pitch Primer in my country's App Store?

Pitch Primer has been released worldwide.

Will Pitch Primer work with double bass?

The app probably doesn't work very well with double bass, at least with the lower registers. With a cello it works fine but with double bass's lower registers may jump an octave at times.