Which font and size does apple use for the navigation bar title?

iOS12 – iOS15 Large Title – System Bold 34 (San Francisco)

[UIFont boldSystemFontOfSize:34]

iOS9 – iOS15 Regular centered title – System Semibold 17 (San Francisco)

[UIFont systemFontOfSize:17 weight:UIFontWeightSemibold]

iOS8 – System Semibold 17 (Helvetica Neue)

[UIFont systemFontOfSize:17 weight:UIFontWeightSemibold]

iOS7 – System Bold 17 (Helvetica Neue)

[UIFont boldSystemFontOfSize:17];

Nice link about typo in iOS
https://learnui.design/blog/ios-font-size-guidelines.html