http://pin.it/86wtoPI is a great resource for grammar worksheets. This would be great for extra grammar help, or the base for a entire unit.
http://pin.it/gnK0WpL is an entire board devoted to different apps teachers can use for various classroom settings. I do like the music cues app, as well as the tips for making writing can be easier using Google Apps. This would be fantastic for a 1-to-1 classroom!
Finally,
http://pin.it/KBtg0Uf provides TONS of ways to teach internet safety and digital citizenship-- a must when having students use their devices for education.