问题
I'm developing an application which supports IOS8 and above and I want to use San Francisco font. This font was introduced by Apple in iOS 9.
How can I us this font on an iOS 8 device?
回答1:
You can't Apple does not allow you to distribute the font with your app. So there is no way to get it legally in your app bundle to use it on iOS 8 devices.
You can clearly read this in de license agreement on https://developer.apple.com/fonts/
A.Limited License. Subject to the terms of this License, you may use the Apple Font solely for creating mock-ups of user interfaces to be used in software products running on Apple’s iOS or OS X operating systems, as applicable. The foregoing right includes the right to show the Apple Font in screen shots, images, mock-ups or other depictions, digital and/or print, of such software products running solely on iOS or OS X.
No Transfer. Except as otherwise set forth herein, you may not transfer this Apple Font without Apple’s express prior written approval. All components of the Apple Font are provided as part of a bundle and may not be separated from the bundle and distributed as standalone applications.
来源：https://stackoverflow.com/questions/37345768/can-we-user-san-francisco-font-for-ios-8-applications-if-yes-best-way-to-user