My school (Ethel Walker) has implemented a 1:1 iPad program this year and though I've worked with them in the past, leading my classes through technology snafus as well as intense Latin grammar has led me to think at length on what the best use of this (or any) device truly is.
As a platform for textbooks, I couldn't be more pleased. I spent my summer creating my own Latin text which with any luck will be published at the end of this year. As it stands, I'm using it for my Latin 1 and 2 classes and I must say the ease of creation and the depth of media that can be added is impressive. Videos, art, flashcards, built in quizzes; all easy to create and great resources for my students to have at their fingertips. It has already taken my flipped classroom model to a whole new level.
For sharing and collaborating, I've found a plethora of uses as well. My personal favorite as apps go is Educreations. It's free and allows my students to make their own instructional videos on grammar topics that they can then review at their leisure before assessments. It also allows me to quickly create a voice-over of a powerpoint to help students with questions. Something that, with all of our busy schedules, is priceless.
As a platform for tests and quizzes however I am still dubious. I so desperately want to make the best use of this amazing device but haven't found a truly reliable form of quizzing or testing. A lot rely on multiple choice, true/false, etc, which is by no means ideal. But then I realize that my iPad is in fact a tool to aid my teaching. It isn't the only thing at my disposal and sometimes nothing beats pen and papper or a white-board!
In closing, I'd like to offer my experience (short though it be) and help with any questions about the iPad or textbook/video creation.