You can also use their online practice for some low-stress grammar work. Students can just do it online, or you can print out the Grammar Bytes answer sheet for them to record their responses (though since the site gives the answers away, it is not a good assignment for grading and assessing).
Each practice explains what the concepts are that it is practicing, then provides questions like this:
If the student gets it right, they win a prize!
Plus a satisfying "WOW!" from the computer simulated audience!
If your student is wrong, they still get a prize, but...
Not bad for some formative assessing and for some laughs as kids hear "WOW!" or "MOO!" ringing out from various computers across the room.