1. Tap the Paintbrush button (in the lower left of the Timer screen)
(Note, if you don't have the Paintbrush button in your Timer screen, you need to purchase the Customization feature. You can do this by tapping the Store button at the top of the main menu.)
2. Tap "Font"
3. Do you want to customize the font for just this blind level, all blind levels, or all blind and break levels? Tap your answer:
4. Scroll up and down to see all the fonts. When you've found one you like, tap it.