The app store ‘hello world’ is the tip calculator

I built a tip calculator for the iPhone App Store, mostly as a learning exercise. But the thrill of having my first binary approved, and hitting 2,700 downloads in the first day made this whole thing about more than learning…

…more from the seedy world of app trades and icon rages, after the jump…

The guts of the app aren’t that impressive, the thing multiples, the thing divides, big frakkin’ deal. When people find out I’m an App Store developer, sometimes I’m even embarrassed to describe what I built.

But the truth is that gradually evolving the interface, noticing user’s needs and reacting to their feedback is immensely gratifying. It’s taken eight or nine iterations to bring it to this level of fit and polish, and it’s paid off. I’m proud to have one of the highest rated (and most imitated) tip calculators in the store. Embarrassment has given way to pride…

…here’s the sketch that started the whole thing:

And here’s the two major visual revamps of the interface:

Three things I didn’t expect,

  • I spent more time in Photoshop than I did in XCode, tweaking and tweaking and tweaking the pixels to make it all intuitive and seamless. And there’s 852 lines of code in the whole thing. Which is a lot if you consider this is a simple tip calculator.
  • App Store customers are violently passionate about their icons. I’ve banished apps from my first home screen for ugly icons, so I definitely understand. Every tweak I’d make would bring a passionate uninstall threat from at least one reviewer, every single one.
  • I’m still not a millionaire.

The app now is called Bowtie Tip Calculator, [update: it looks a lot nicer than the old screenshots above], and you can get it free in the app store.