No specific info about version 3.1. Please visit the main page of Chromaphone 2 on Mac Informer.
Eight-voice standalone is a MIDI synthesizer with built-in effects.
This app gives you access to various background sounds.
Matrix 12 V is a professional audio synthesizer for Mac computers.
Noi is a freeware noise generator and nature soundscape player for Mac OS X.
Circle Wavetable Generator is an easy-to-use synthesizer program.