So I emailed Flipboard support to ask about font resizing their reply;
Hello Brandy,
Thanks for your email. To change the font size, swipe to select the Search charm. Type “Display Settings” and adjust the size. While Windows 8 doesn’t support the ability to make the font larger—default and smaller are the options—Flipboard may add font adjustment to the application Settings in the future. Let me know if you have any further questions.
Thank you,
~ Bettie Utas
Community Support Lead