I think its a very good tool for students who is learning to write, they could be confident to write sentences and they could know fast when they are wrong
Useful tool for individuals, but not for education
Overall the tool serves as a good way for students to correct their writing and create better quality papers, but it is on them to take the extra step to figure out what they did wrong. Since they are not encouraged to do so and given the answer, this is often not to be the case. It is a great tool for final correction, but shouldn't be relied on for education purposes.