I found the Health app has a mindfulness section, yet I did not find in the documentation how to contribute to that section. Concocting a web search for this requirement returns me a collection of worldwide retreat centers... could you direct me to something meaningful?
I found HKCategoryTypeIdentifierMindfulSession.
A category sample type for recording a mindful session.
This is iOS 10+ only. I think they created this for the new Breathe app to track how much time you spent meditating. It is awesome, you should use this if you building meditation app or something in this area.