The first is a great guide on how to actually build an iPhone application. The folks at Mashable have posted it and the developers who put it together documented the entire process of the development of the application - including all of the choices that they had to make during creation of it. Great read for any developer who wants to get moving (and they made the application in about a month):
Building PhotoKast: Creating an iPhone app in one month
The second is finding from Pinch Media (through Tech Crunch) that most iPhone applications only last 30 days before usage drops off dramatically:
It looks like after the intial download, users test out the free application for a minute or two and then it sits idle on their desktop while they look for other, more interesting ones.
As an iPhone addict, I can say that this is certainly true. I just did an audit of my pages of applications and of the 42 that I have, I probably use 4 daily, 6 weekly and the rest are just there. The cool part about the free section of the application store is that you can try out and download new applications daily.
The problem for developers is that there are so many great ones already and getting the attention of a savvy user is hard - even after they've downloaded it.
