I have used this app for this past school year. I teach music for PreK through 12th grades. I hate doing grades, evaluating behavior, weighting exams & homework,recording attendance, etc. Id rather spend my time teaching. Paper gradebooks are tedious for me. I have to turn in weekly grades for my secondary kids, do midterm quarterlies, interact with parents, just like the rest of the teaching world.
However - its just a few clicks every day now, and allows me to enter notes for elementary behaviors, send a quick email to a parent or student, send my weeklies to the administrator - customized with whatever data he requires. The reports function is incredibly rich and flexible.
At the end of the year, I print out the data for permanent records, and backup via Dropbox, where I can use a second iOS device if necessary in case I leave my iPad at home for some reason. It is totally worth it, my life is much easier now!!