A new survey of more than 2,100 app developers released jointly by IDC and mobile development platform vendor Appcelerator Tuesday found that 78.6% of developers were interested in creating apps for Android smartphones during the first quarter of 2012, down from the 83.3% in Q4 of 2011 and down from around 87% in Q1 of 2011.

“Massive platform fragmentation is a big reason that we’re seeing this decline in interest,” says Mike King, a former Gartner analyst who now works as Appcelerator’s principal mobile strategist.  “If you look at all the other numbers such as Android smartphone market share it’s on the upswing, but for app developers it’s a real challenge.”

Even so, Android still easily generates the second-greatest level of interest among mobile developers, as only Apple generated more with 89% of developers saying they wanted to make apps for iOS.  And Android is nowhere near seeing the dramatic free fall in developer interest currently plaguing Research in Motion’s BlackBerry OS, which saw its developer interest plunge to 15.5% in the first quarter of 2012, down from 20.7% in the fourth quarter of 2011 and down from around 37% in the first quarter of 2011.