Has anyone found fun things to collaborate on with their friends online?

Couple questions:

1. What would be the best tool to use to have an always active "room" that you and your friends can join and leave that supports group video chatting? Ideally you don't have a to start a video call every time someone wants to connect, you have something similar to a discord voice chat that people can pop into at their own discretion (except it has video).

2. Do you have any ideas on things you can use to spend 30 minutes on at a time and work together with people online? I'm thinking about something like creating a Minecraft world that you open up to your friends that you slowly start building something together over time. An idea that allows you to pop into something, work on it for a bit, see where others have got to and continue on.