Apple now uses their proprietary typeface San Francisco (SF) for some of their branding and communication online, in print, in retail stores, and on the products themselves.

Designed in-house at Apple to replace Neue Helvetica as the system font family for OS X and iOS. Technically named San Francisco UI, but Apple did not introduce it that way. San Francisco Compact is a variation intended for Apple Watch. The family has 6 Text weights with italics, and 9 Display weights without italics. San Francisco is licensed to registered Apple developers for exclusive use in Apple operating systems. Here's the download link