You can't change the actual font on your iPhone, but you can change the font size in a couple of ways. The Settings app lets you shrink or enlarge your iPhone's font in nearly every app at once. If ...

Signal, an encrypted messaging service, lets you change the font size of the app's display and messages. You can change your font size in Signal on the platform's desktop, Android, and iPhone apps.

Besides a pill-shaped tweak for the Suggestion strip, Gboard’s next visual change is a dedicated keyboard Font size setting. Update 10/15: This Gboard Font size setting is now widely rolling out with ...