I don't think Apple will ever allow native apps to be deleted from the iPhone (& stored on iTunes)...
It's annoying, but I just bundle them with the countless apps I never use, lol... (See below)
https://www.aulro.com/afvb/images/im...2009/03/54.jpg
Also, the most child-entertaining feature on my iPhone is without a doubt a Pixar video (from iTunes - about $5), called Boundin'... My nephews must have watched it around 80 times (in SILENCE :D)

