The user interface design language for spell was well thought out & easy enough to understand even by someone who has no background in programming or coding at all! It's not very customizable but this can be fixed with some more work from their side as they are open source software.
I believe it would have been better if there were options like python3 instead of 2 which might make things easier when using anaconda (which we use). We used NLP techniques mainly text classification tasks such us sentiment analysis etc., This solved our problem regarding predicting customer rating/feedback after providing them services so far.