Hello,
the Project is clear to 80%.
we just need someone who code the app that the data which is load from a online xml will be saved, and not delete, so that if someone open the app whiteout internet he will find the things which he had load before ( in the time he has internet ).
Thats it.
Greetings, i'm a iOS senior developer. As far as i understand your needs, you just need to store data locally in the app sandbox, to let user access data if the network connection is not available.
Let's do it in some hours.