I tried open camera, but was not able to have a variable ISO and a fix time (not sure if my phone has a variable aperture). It’s the same for the stock camera app and among friends, colleagues, and family, no phone/app seems to implement it.
I am photographing my children and they tend to move fast, so in automatic or ISO priority modes, the selected time/ISO combination do not fit most of the time.
I know I could have asked at open camera forum, but am not too interested in an SourceForge account. Furthermore, the topic is very general.