AppStoreHQ founder Chris DeVore, whose site tracks apps for Android, iPhone, iPad and HTML5 by crawling their respective app stores, created an eye-opening Venn diagram of how app developers for iOS (the iPhone/iPad operating system) and Android are clustered.

DeVore says he and his team crawled their own database and manually checked 4,500 entries by hand to make sure there were no major bugs in their approach.

The resulting chart speaks for itself. Of the 51,972 app developers listed in AppStoreHQ’s database, these stats can be extrapolated from DeVore’s count:

  • 43,185, or 80 percent, develop solely for Apple’s iOS.
  • 8,787, or 17 percent, develop solely for Google’s Android platform.
  • 1,412, or 3 percent, develop for both.

Neither iOS nor Google has anywhere near a lockup of the app-spender market. So why don’t more developers create apps for both platforms? “We were actually impressed at the numbers of cross-platform developers,” DeVore said, “and particularly the number of recognizable brand names that had already made the leap to Android: Gameloft, Facebook, AOL, Amazon, Warner Brothers, Intuit.” DeVore has shared a spreadsheet of the top 100 most talked-about cross-platform developers.

DeVore thinks Google has made it pretty hard for Android developers to get found and to make money, but he believes the sheer number of customers they can reach and sell to has encouraged them to jump over the hurdles.

Don’t miss MobileBeat 2010, VentureBeat’s conference on the future of mobile. The theme: “The year of the superphone and who will profit.” Now expanded to two days, MobileBeat 2010 will take place on July 12-13 at The Palace Hotel in San Francisco. Register now. Tickets are going quickly. For complete conference details, or to apply for the MobileBeat Startup Competition, click here.