You like the error tracking sentry.io provides, you want to self-host it, but the setup takes up too many resources? Then https://glitchtip.com/ might be something for you. It is a FOSS reimplementation of the sentry backend with most important features. You can install it using docker following their guide, but if you like me like to install things from stretch without docker, then this guide might be for you.
You want to stream a game like the Jackbox Party packs to your friends, but use the same computer for voice chat at the same time without that audio appearing on the stream?
Then this might be a solution.
Installing Jitsi Meet on your own server allows you to Voice-/Videochat with multiple people and use features like screen sharing. Unlike other services it works without accounts or desktop clients — you just need to share a link with others.