I have just released an update for WaveFlower, a toy app I created some years ago:
This apps the origin of the music visualiser in Toot!. It uses the microphone instead, so you can sing to it, or play your favourite instrument, or just make weird noises at it. It will respond by drawing shapes based on the sound waveform. It can be pretty mesmerising!
Server run by the main developers of the project It is not focused on any particular niche interest - everyone is welcome as long as you follow our code of conduct!