Audacity 3.1.3 does have a spectrogram view. With your file open, click the little down-arrow next to the name of the file in the upper left corner of the file's window, and select Multi-view.
Older versions worked (although I never did like the UI), but the latest version does not work at all on my Samsung Galaxy S10.
Smart Recorder is very minimal, but at least it works. I've been able to get decent recordings with it.