The video is for AVsitter™ (2013), which I’ll call AVsitter1. I couldn’t find an AVsitter1 video by AVsitter.
If you don’t know, AVsitter is a tool for building and controlling animations in things, furniture mostly. It serves for simple to complex animation control. There are videos and various other tutorials on how to use both AVsitter1 and 2. (AVsitter2 on YouTube) These days most are AVsitter2™.
There will be one final update of AVsitter1. Some support will continue.
AVSitter2 has been around since 2014. It seems quite popular in Second Life™. I have no market data. So, I have no way to know ‘how’ popular. nPose is a similar tool. Both avoid the use of pose-balls. Both are reasonably easy to use. It looks like AVsitter2 requires fewer clicks.
I haven’t used either AVsitter1 or 2. So, I don’t know what is different between 1 and 2. However, the following AVsitter2 video will show how different 2 is from 1.
Obviously, the newer AVsitter2 is much easier to use. I have no idea how complex you can get with it.