With Contacts Journal v6.0, you can now change the font size in the Contacts Journal app (for iOS15 and above). You can either change the font size for only the Contacts Journal app; otherwise, the Contacts Journal app will use the system font size which can be changed from the Settings app.
Change Font Size in Settings
From the Settings app -> Display & Brightness -> Text Size, you can drag the slider at the bottom to increase the system font size. Note that this will increase the font size for all your apps that support this functionality.
You can enable even larger sizes than the standard sizes. To do this, go to the Settings app -> Accessibility -> Display & Text Size -> Larger Text -> turn on the "Larger Accessibility Sizes".
Change Font Size for only Contacts Journal
If you don't want to change the system font size, but still want a larger text size in the Contacts Journal app, there is a way to do so:
- In the Settings app -> Control Center -> in "Included Controls", add the "Text Size" control if it's not included
- Now open the Contacts Journal app, and swipe from the top-right to bring up the Control Center screen
- Select the "Text Size" control
- Select "CJournal Only" and then increase the text size