I’m always delighted to highlight the efforts of small independent scientific software developers who support MacOS, iOS etc. I wrote iBabel because it was something I was interested in and made it available because I felt would be useful to folks interested in cheminformatics..
Recently I became aware of Stephen Sharpe’s website https://sharpy.site where you can find a number of interesting small apps for MacOS and iOS. These range from an app to identify sharks’ teeth, to vapour phase IR spectra.
Let me know if there are any others that you would like me to mention.