I've written a "toy app" for OS X Touch, a version of my Remote Remote GH for MythTV application which acts as a remote control over the wireless network to control a MythTV. It's a toy in the sense I am mainly using it to learn the iPhone SDK, and not to earn money, or even a large user base. I don't expect it will find a large following, I was just learning the ways of the iPhone.
Coding for the iPhone is different. Not so much in the GUI classes or the tools, but in the outlook it requires of the engineer. I was working in a resource starved environment; one in which I needed to take care not to run out of memory, not to use network unless needed, and not to spend a lot of time launching or quitting. An environment, where I had to justify every button on the remote control as space worthy. I leaned heavily on Apple's performance tools, much more than I would on a Mac. And, I refactored constantly. Every time I learned something new, I would change my code to work better and better fit the SDK way.
I also needed to use SQLite extensively, and felt compelled to adapt the QuickLite framework to both Objective-C 2.0 and the iPhone. If Tito Ciuro reads this, please send me an e-mail.
And finally, I'm quite proud of most of the artwork:
It's harder than it looks coming up with simple, thematically consistent, iconic graphics. Thanks to my wife for telling me try again after my original app icon design mashed together a picture of a widescreen TV with a remote drawn in perspective. I went with a simple rendering of navigation buttons, which I liked so much I made the buttons part of the actual GUI.