This app seems kind of like a mean joke. It's somewhat functional, but so lacking in helpful instructions of any kind and so many useful features that I found it far more with it to pay $10 for a better app. Plus, a fair number of bugs in here. I've had to force quit it several times in a few days.
If I had to guess (actually, even if I didn't have to), the author wrote one editor and skinned on a bunch of languages as different apps to sell. This can be done well, but it takes care and attention to each language's needs. That care does not seem to have been taken, in this case.