Typography in Interface Design

Typefaces suited for digital interfaces tend to have a high x-height and easily distinguishable letterforms. 

Gotham

Gotham was never intended for use on user interfaces, but it performs relatively well in use. Though it has a small x-height, its letterforms are all differentiated with ease and often the type is set in the heavier fonts in the family which helps to aid legibility and readability. The typeface allows for rapid reading due to its compact form. Gotham Medium is used by Tesla in the Model S and Model X.

San Francisco

San Francisco was designed in-house by Apple for Apple Watch. It was designed specifically to perform optimally in small screen environments such as a smartwatch, and it achieves this through its high x-height and differential letterforms. Whereas Helvetica performs very poorly in a digital environment because of its similar letterforms, such as i and l, San Francisco was designed specifically to avoid this.  It has been expanded from Apple Watch to both iOS and macOS.

Roboto

Roboto was designed by Google for use in Android software and within the Material Design language. It has a wide usage scenario, ranging from phones to TVs and car infotainment systems. Its high x-height and condensed form make it ideal for small screen environments like phones and watches. It performs well in the space it was built for, and although Google describes it as "modern, approachable" and "emotional", some have criticised its military-esque stern-ness. Even a recent redesign failed to make it feel friendlier. 

Helvetica Neue

Helvetica Neue was used temporarily by Apple in both iOS and macOS. It was used after Lucida Grande and before San Francisco. It received much criticism during its short reign due do its inability to scale well and the similarity of some letterforms. Erik Spiekermann said of it: "Helvetica sucks. It really wasn’t designed for small sizes on screens. Words like 'milliliter' can be very difficult to decipher."