Jamulus is a cross-platform application to jam with friends online
https://jamulus.io/
Sublive is a software package for Windows and Mac for low-latency audio collaboration.
Farplay helps users get rhythmic synchrony online and works on Linux, Windows, and Mac
https://farplay.io/
Looking for VOCALOID trading cards?
Check out Sakura Blossom Trading Post
Chris Grimmett