Reiska,
With respect, the app idea alone is NOT the way to go in my opinion.
Yes, it's fine if you have a snappy internet connection to download the app and the various subjects...but it took three days for me to update Pages and Numbers on my iPad in Nigeria with it plugged in, and on the pitiful wi-fi we have in the residence there. We don't even dream about doing an IOS or OSX update there! I could load the base app while in Germany or the USA, but then when I want a particular subject for the app to display; to study or refer to, and it isn't on my tablet already, forget about it while in Africa....whereas, having a DVD with ALL of the available docs, videos, and instructions is much more portable.
Just my [2cents]
Cheers,
Frank