There is a custom font San Francisco, designed by Apple as the system font for iOS, tvOS, watchOS, and macOS. The font is very legible on whichever Apple system or display you are viewing on. As a developer or designer, you are going to enjoy having access to this font for things like mockups and other related works.
If you don’t have the San Francisco font on your Mac computer. You will be glad to learn that Apple has availed it as a free download for all; of course to those installing it on Apple devices.
Downloading and Installing San Francisco fonts
Go to the Apple Developer Fonts page and select the San Francisco font pack. Next, you will need to mount the DMG file you have downloaded and then access the disk image using the Finder.
At this stage, you should be presented with the font limited license files elaborating on the usage limitation. Most of the nitty gritty here are meant for developers, but as a general user, you may want to be acquainted with them so you know the limitations.
Next, select each individual …read more
Read more here:: How to do I install San Francisco Fonts on my Mac Computer?