How many apps do you really need for your iPhone?

Apple dominates the smartphone market today, allegedly because of its 100,000-plus applications. Does that mean it will be completely indomitable when it has 200,000? God-like at 300,000? And Microsoft-esque at 400,000?

Of course not.

As former Googler and current Apache Software Foundation developer Greg Stein points out, an app store's dominance has little to do with sheer volume of applications and everything to do with their relevance to you:

The [Google] Android Market is definitely behind--it is missing some nice applications. But not many! All the apps that I used to have on my iPhone are now available on my Android phone. Thus, Apple's App Store has zero "advantage" for me. How many other people are like me? Or conversely, how many people want and use all of those 100k applications?

I think the conversation should be rephrased into "do the apps exist that a typical consumer wants?" rather than focusing on a mere count. That is the success of any app store.

Of course, it's likely that the more volume, the more likelihood that applications will exist to suit the needs of a greater percentage of "typical consumers," but Greg's point stands: if most of us care about a core 100 (and actually install, on average, 65) applications, does it really matter if there are 99,900 more?

To compete, Google (or Palm or Symbian, etc.) doesn't need to write more applications. It simply needs to write core applications that its customers care about, and then ship a ton of phones so that developers will write the remainder, as Google's Chris DiBona argues:

This is going to sound really cynical, but the only thing that really matters is how many of these we ship--how many Android phones. There is a linear relationship between the number of phones you ship and the number of developers.

Or, as Google's Andy Rubin puts it, "The app thing is a reflection of how many phones you've sold. That's what developers invest in."

Still, most people don't need to wait years until Android (or Symbian or Palm or Microsoft or...) catches up with Apple's application ecosystem. Most people already have every application they could possibly want already available for their chosen platform.

Even in developing markets, which can have significantly different application needs than the developed world, Nokia and others are working to ensure widespread availability of relevant applications through initiatives like the Calling All Innovators program.

Sure, there's a risk that by investing in a declining platform, consumers could end up losing out on future, must-have applications. But this isn't a problem for growing platforms like Google Android--or even for Windows, which has been in decline. At some point, Microsoft will figure mobile out.

I love my iPhone, but I'm actively considering Android. Of my most consistently used applications, as reflected on my iPhone home screen above, the only application that is still missing from Android is Rogue Touch. Give me that, and I'll have all I need.