Ask HN: What tools are game changers for communication in fully remote teams?

I work at fully remote company. We do a lot of meetings. In those meetings, people go on and on talking about complicated workflows and technical discussions. However, I'm sure most of the others don't follow completely. Voice quality is sometimes bad. I'm sure people who work fully remote can list additional problems.

In physical offices, we have whiteboards that help us explain and keep others' attention, we have facial expressions that help us know when people have difficulties understanding, etc.

So have you discovered a tool or a way to significantly improve communication when working with a fully remote team? If so, please share your experience.