We are developing a conference tool called openslides based on Django and Angular 7. The software deals with speaker management, display of content on different media projectors, polls etc. Here is an image film which shows the tool in action. Last year we had a test run for Amnesty international.
The current version is 2.3 (version 3 with fully mobile integration and material design is in the pipeline and will be released soon). Lately we implemented a basic real time chat with WebRTC as a plugin.
Our project is hosted on github.
If you are looking for entry-level issues we have the good first issue hashtag.