I am actually an instructor for Japanese and was evaluating this program for students to practice with. Let me first say I very much like your writing sections for hiragana and katakana, as it works very cleanly for a beginner.
I have come across a word error, though… minor since I think most people looking at the computer words will not be looking at the romanji spelling anymore, but I couldn’t just ignore it. XD
The word “website” is written correctly in katakana (uebosaito - with a half height e after the u), but the romanji says ukkbosaito!
To be fair, there is -not- a good way in romanji to indicate that the e is small. If you listen to your speaker say “up” or ue, you will probably hear the difference. In up, the u and e sounds get equal time. In the start of website, the u and e are sort of mashed together to try and imitate something close to a ‘we’ sound that modern Japanese doesn’t have (modern Japanese only has wa and sort of wo for w sounds).
ANYWAY. Please connect with your Japanese reference person for advise on how best to fix this, but at the very least, the romanji spelling should be edited so that it works closer to correct for the flashcards.