Programming for the iPhone SDK is easy for existing Mac programmers, since they already know Objective-C and most of the libraries (API) from Mac OS (Cocoa) are still there. The thing that is different is no mouse, no keyboard, no menus, no dropdown menus, far less screen space, and your app can't run in the background so it has to "pretend" to the user that it has been there all through his phone call that he accepted - i.e., come back up at the exact state that he left it in.
For programmers who have not done Objective-C but are experienced in C programming, it should take a few weeks, even less if they know any object-oriented language such as Java, Ruby, Python, or even C++ to some extent. All they have to do is learn the particular ways to do the same concepts they were already doing on their current platform.
Objective-C is a superset of C.
Tell me more about the WP app you mentioned. Basically text, images from the Photos library, and then mail it off?
Originally Posted by Bergermeister
Just a couple of thoughts off the top of my head at 5:50 in the morning after no sleep:
A simple WP-like app would be great. Zeptopad has its good points, but also limitations. The user should be able to choose a paper size (A4, for example), add text boxes, sketches and photos, though the size restraints will make photos tough. Save as photo and mail away.
A simple audio recorder/editor that will allow insertion at any point, cut and deleting. Most of the current apps seem to only allow tacking on to the end of a recording.
Some apps like FourTrack have a great way to get data off the iPhone and on to your Mac using WiFi. This could be used for the above two apps.
A simple animating app that saved to movie would be awesome, but it doesn't meet your criteria.
How hard is the iPhone to program for? I learned BASIC way back in the dark ages (aka, the early '80s) and haven't done any since. However, I have an idea for a product for my current company but nobody can program...