If you have an Apple Watch, then you’ve undoubtedly noticed that it sports an entirely different system font than your iPhone does. Typically, you’d need to install performance-impacting or battery-guzzling add-ons to change your system font, but with a new and free jailbreak tweak called Compactor by iOS developer Jamie Bishop, you can bring the Apple Watch’s native font to your iPhone without these ill side-effects.
As depicted in the screenshot examples above, the Apple Watch’ system font, also known as SF Compact, is both smaller and more legible than the iPhone’s native system font.