Mobile app and games discovery provider Mplayit published a comparative list of most-popular apps on the iPhone, Android and BlackBerry platforms. It's based on a survey "of 42,000 visitors to Mplayit on Facebook between 20 December 2009 and 5 January 2010." One question to ask is whether these apps are in fact intrinsically the strongest in their respective categories or whether other factors are fueling their popularity. 

The Mplayit release doesn't attempt to answer the question or explain why certain apps may be popular across platforms. In the case of a Yelp, Facebook or Pandora, there's a strong brand there that transcends the mobile OS and that people are responding to, for example. But the fact that some "no-name" apps beat out brands such as "Buddy Mob" on beating Facebook or Aloqa beating Yelp on Android (during the survey window) suggests that a compelling or engaging app can drive adoption without substantial brand equity or recognition.

Here's the chart: