Room Analysis-How?

So I’ve seen a number of YouTube videos and the like where people have conducted an analysis of their listening room or home theater to help optimize speaker placement, room treatment and subwoofer settings. It appears that they use a variety of software and microphones. And then the result is a series of graphs that show high and low spots in the frequency range.  And the it helps them with placement and room treatment. I like my system and it sounds pretty good to me in my room. That said, I’ve always been a little intellectually curious as to what the charts and graphs would say about my room. And if I could make it sound better.  So are there companies that do this sort of analysis you can hire? Or is there downloadable apps that are relatively dummy proof and user friendly while doing a good job?  Other?