The iOS side is trickier because Apple has developers implement these kind of features in app-specific extensions.

Unlike Android, I can't say "just import this", and the appropriate extensions appear. I have to walk users through the process of creating an extension properly that hooks into this.

The "host yourself" feature is a big deal in HIPAA, GDPR, and IRB-governed contexts, where third-party data disclosure is discouraged or prohibited.

Working now on getting it packaged up with documentation. Not a big deal for the Android side of things, but a bit trickier for iOS...

Also, unless you are going to pay someone to maintain it, DO NOT create mobile research apps in JavaScript. There's simply too much churn in that ecosystem that after 3 years, bringing one of these apps back becomes a painful exercise in JS library and code archeology and native integration.

When you are forced to ensure that your project is build-able under CI, not only do those weird quirks get surfaced REALLY QUICKLY and have to be fixed to pass a build, BUT the CI build instructions function as a form of documentation as well.

At home, I still have copies of the SGI MPI programming manuals for these machine with instructions for writing the massively multiprocessor code needed to make the most of these machines.