I found that there's awesome project called 'coding-night-live'. it's a web-based communication application for codelabs.
Popular web-based applications like Slack, PingPong, etc., do exist for hosting interactive seminars, but none are customized exclusively for the codelabs. coding-night-live is the light-weight, installation-free, web-based solution for the awesome codelab-thristy programmers!
codelab is a fun step-by-step, seminar-based approach to developing a software together.
- Youtube introduction for coding-night-live v1.0 is here: https://youtu.be/EgOmuShXVNE
- coding-night-live github: https://github.com/dduk-ddak/coding-night-live