iOS 16 support

Some older devices cannot update past iOS 16. It might be a good idea to make a version of this for those devices.

Note: This was attempted and shelved in the past. You might see remnants of it around; those are what this ticket tracks. If you want to pick them back up and work on them, reference this ticket.

Start by locating the remnants of the previously attempted iOS 16 support and reviewing why that work was shelved. Determine the scope needed for a version that runs on devices limited to iOS 16, then verify that the app builds and functions on the supported older devices; the issue does not name specific files or tests.

Written by the indexing model from the issue text.