Kaizena
https://kaizena.com/: Google Chrome add-on (free). Both students and teachers need to have it. (It only works on a desktop/laptop).
It allows you to edit text, add text and voice comments.
You can also create rubrics.
It also allows you to create a lesson bank, and insert them as a comment.
http://blog.kaizena.com/post/170016427695/all-kaizena-features-now-available-inside-google
Tutorials on how to use Kaizena (Spanish)
My colour codes:
- red: very clear, obvious mistakes/errors
- yellow: the sentence does not sound natural, or is not completely accurate
- green: I liked it, there's a nice structure/vocabulary item being used...
- blue: what the student wrote is OK, I'm just making other possible suggestions (to broaden their vocabulary range, to sound more natural, more appropriate for their level...)
- Individual elements /skills can be added to the rubric.
- ...or else generate a whole rubric from those skills.
- A grade can be given. Alternatively, only feedback can be given without any grade.