Quartz:

The Apple Watch typeface, on the other hand, was made to do one thing: read well on the (tiny) screen it was designed for. It borrows heavily from DIN, a legible and space-efficient typeface introduced in Weimar Germany for road and train signs, but updates the letterforms with rounder shapes that are better suited for a digital setting.

Yes! Love that font. It’s beautiful, legible, simple and strong. And has more character than Helvetica. I used DIN for all my signage when we had Einmaleins as a┬áretail store.