Looking for Room Measurement / Speaker Setup Software

I am trying to find the best location for my speakers.  Tuning by ear has been effective but I still like to see what the frequency response looks like.  I also have a lot of diffusion/absorption products I can use to tune so I'd like to see their effect before & after visually.
As far as an EQ Preamp, I had a DSPeaker Anti-Mode 2.0.  While it certainly adjusted the room response it degraded SQ.  I had no idea how much until I tried it with/without in my system.  Maybe it was the extra cables involved but it was anything but transparent with my equipment.  I use Audysssey in my HT setup but I haven't heard anything transparent enough I'd use for my 2-channel.  I'm not saying something that good doesn't exist, just that it would probably be out of my price range.
Ian

Phone App ...

Which phone app would you recommend?

I use the parametric EQ in Roon to tame a 7db peak @ 40hz in my room.  I can control the frequency, gain and Q all in the digital domain....Completely transparent.  I used the XTZ Room Analyzer 2 Pro and my computer to measure the room.  You would have to subscribe to Roon to use the free EQ supplied with the service.  I wouldn't be without Roon to integrate and sort my digital files along with Qobuz or Tidal.

RTA Analyzer is Free to install with Peak and RMS.
Spectroid features a Spectral Graph with Peak and RMS.
These will give a measurement at a single position.
Also a test tone LP / Disk and may help with the setup of the Super
Scoutmaster TT.
Try one see how it works for you.