Hi. You should be able to install custom fonts. Find the help screen and search for "Custom Fonts" which should provide instructions. I've included the instructions below.
You can find a greek font here:
http://www.bible-researcher.com/sblgreek.htmlLet me know if you need more guidance.
Ernie
Custom FontsWhile Android's built in fonts are somewhat limited, you can install your own custom fonts through a USB cable:
1) Attach the device to your computer and find the following directory on your device:
\Android\data\com.orangeorapple.flashcards\files\Fonts(You may need to instruct the device to mount as a disk drive when attaching to computer.)
2) Copy your font files to this "Fonts" directory. Font files must have either a .ttf or .otf extension.
3) Restart the app then choose the font the standard way in the Deck Options screen.