Our app supports the Dynamic Text Size feature of iOS. In order to change the size of the fonts we display.
Open iOS Settings > Display & Brightness > Text Size. Use the slider to increase or decrease text size.
Once done with the change, launch our app. Some HTML formatted emails may not properly support Dynamic Text. In those cases, you can use pinch and zoom to get a better look at their content.
Please let us know if you see any font rendering issues by sending a screenshot into support: Settings > Help & Feedback > Contact Support.