Mark My Words

I've just tried Mark My Words. If I need to give comment to every piece of writings, this is a fantastic tool because this tool can help us save a lot of time for thinking of and writing comments. If my assignment is marked in this way, I'll feel so happy and grateful.
However, I'm teaching in a primary school so I would think from the point of view of a primary teacher and primary students. A primary teacher don't mark compositions in this way because we don't teach all the terminologies of English so we won't write so many comments in the compositions. We will underline their mistakes and let them think or write down the correct words and let them do corrections. In addition, I don't think most of the primary students will understand the comments. Therefore, in my point of view, this software is not very useful or helpful for me.
However, I do think this software is great if teachers need to mark writings on the computer. It is very convenient and user friendly.