Take a look at Dropbox and their IOS app. I believe it does 1-3. There's certainly apps that also do 4. Have a play with that setup for a while, see if it's wor

Take a look at Dropbox and their IOS app. I believe it does 1-3. There's certainly apps that also do 4. Have a play with that setup for a while, see if it's worth putting it all into a custom IOS app (you can then build that using Dropbox's API if you like).