Not the first one I’ve downloaded. No, the first one I’ve written! It’s on sale now in Apple’s App Store, and is the only search hit for “SpinClock”, at least at present. It’s also a big reason why this blog hasn’t been updated recently, since I was giving the project all of my spare time since Christmas.

I’ve been programming professionally for about 20 years, and I’ve done a little Mac OS X programming on my own Mac at home, using Objective-C and Cocoa. So I expected that picking up the iPhone OS and Cocoa Touch would be pretty simple, but the learning curve was steeper than I expected. Apple has changed or removed some of the higher-level 2-D drawing APIs (Application Programmer Interfaces) that I had been using, and there were new animation APIs and conventions that I didn’t yet know (although I would have, I think, if I’d been programming for Leopard rather than Tiger).

There was also a lot to learn and set up regarding the development environment, particularly the code signing and device provisioning. Apple protects the iPhone platform pretty tightly, and I can see why: a rogue application that was able to spread itself from phone to phone would ruin the phone’s reputation. As a result, they use public-key encryption and digital signatures to ensure that they know and have approved every developer and every development device in the process. This doesn’t make the development cycle itself any more difficult, but it did mean some new prerequisites, like requesting electronic certificates from Apple which Xcode needs to use so it can sign my app every time it builds it.

It also turned out that my credit union account was insufficient for use as a developer of a paid app, because it can’t easily accept wire transfers, so I needed to set up a “sole proprietor” business account with a real bank.

It’s been quite an adventure getting started on the iPhone. Now that I’ve been all the way through the cycle (including making one sale to Spain!), I’m looking forward to rolling out more apps this year, and updates to SpinClock.