The developers logged 3,997 distinct devices, the most popular of which was the Samsung Galaxy S II. This figure was inflated quite a bit by custom ROMs, which overwrite the android.build.MODEL variable and cause those phones to be logged as separate devices. 1,363 types were logged only once, and while some were custom ROMs bucking the numbers, a good few were just massively unpopular devices—for example, the Hungarian 10.1-inch Concorde Tab.
It's not only the sheer count of devices that's daunting, either—the spread is also intimidating. It's easy to imagine a practical Android developer who doesn't want to waste time supporting niche devices restricting the app to require high-end hardware and recent APIs, covering only the 25 or so most popular phones, and devil take the hindmost. But in OpenSignalMaps' case, the top 25 devices don't even encompass half of the map, and would still exclude well-known and popular (if old) models like the Samsung Nexus S. The developers would be missing out on over 50 percent of the Android market.