FORTUNE — Suddenly you can see the advantage — both for developers and users — of Apple’s (AAPL) approach of limiting the number of iOS devices on sale at any time to a handful of iPads, iPhones and iPod touches.
Google (GOOG) executive chairman Eric Schmidt downplays the challenge of knowing ahead of time which Android apps will run on which devices. Developers complain about “fragmentation” of the Android ecosystem. He suggests that they think of it, instead, as “differentiation.”
You can see a live, mouseable version of the chart at OpenSignalMaps’ website here. The products represented range from the popular Samsung Galaxy SII (61,389 downloads) to more than 1,300 single downloads from relatively obscure devices such as the Concorde Tab (a 10.1-inch Hungarian tablet), the Lemon P1 (a dual SIM Indian phone), the Energy Tablet i724 (a Spanish tablet aimed at home entertainment).