If you want to keep yourself up to date with what’s going on, or what has been published lately, on how to develop more accessible mobile apps, make sure you subscribe to Accessible Mobile Apps Weekly by @RobinKanatzar from @accessibleapps.
You may also find interesting...

Toggles or UISwitches are often found separated from the label that precedes (and describes) them; with an unclear label; missing a value, trait, or hint; or even not being actionable at all.

Make sure you support Dynamic Type up to the largest text size available. Take into account that there are five extra accessibility sizes available from the Accessibility Settings. It can make a huge difference for lots of users.

You can add an observer to listen for changes in the content size category, in case it is more convenient than overriding traitCollectionDidChange(_:).
Content © Daniel Devesa Derksen-Staats — Accessibility up to 11!