Jitsi is a great alternative to things like Zoom, Google Hangouts, and Skype. It's open source and we use it daily at work for video meetings, happy hours, and building apps that require video and/or voice chat. It's both free as in beer (Open Source), plus 8x8 offers a hosted (paid) version called Jitsi as a Service—or JaaS. If you don't want to figure out the infrastructure or maintenance, but want to customize your video meeting experience then JaaS is the answer. It works on Android, iOS and the web.
This short video covers how you can copy, paste, Jitsi. The first minute shows you how fast you can embed a video meeting in your website. Everything else is just me playing with web hooks, flashing lights, and customizing the colors. Check it out: