Won't let me save – Nitro HTML Review

The app is good and lets me code well, however when I go to save my work using regular letters it tells me I can only use numerical and alphanumerical symbols. So I can't save my hard work! I end up having to copy and paste it to my notes and then repaste it back to the app. As a student going to be an eighth grader in the fall, this app wouldn't be acceptable for assignments.
Review by Bluebirdy_ on Nitro HTML.