I have the feeling that the amount of programmers whose minimum acceptable standard for code is on the level of "garbage in, garbage out" is on the rise. I condemn this development, that's a lack of role models who can transmit the values of culture and discipline.
If I had written that software, I would have made an effort to support the complete Latin script, or at the very least shown an error or a warning for unsupported letters.
Looks like it's based on this paper [1]. It's a recurrent neural network trained on online handwriting data. It means you record how the position of the tip of the pen changes as you write. The training data comes from the IAM On-Line Handwriting Database which has only handwritten English text.
If you want to support a complete Latin script, you would have to generate a lot of training data yourself, preferably in multiple languages. Quite the effort indeed.
