Apple’s iOS continues to be a bright spot among mobile app developers, while disappointing tablet sales and fragmentation are causing developers to pull away from Google.

[ad#Google Adsense 300×250 in story]The latest report from market research firm IDC and Appcelerator shows that the majority of developers are confident about Apple and its mobile operating. According to the study, 91 percent of developers say they are “very interested” in iPhone development and 86 percent are very interested in developing for the iPad.

In comparison, interest in Android phones fell two points to 85 percent and Android tablets fell three points to 71 percent after increasing twelve points in Q1.

“Although technically within standard deviations, these drops stand in contrast to steadily increasing developer interest in Android over the last year and are consistent with an increase in developer frustration with Android,” wrote IDC in its report. “Nearly two-thirds (63%) of respondents said that device fragmentation in Android poses the biggest risk to Android, followed by weak initial traction in tablets (30%) and multiple Android app stores (28%).”

The news for Google’s Android partners is even worse. “While 71 percent of developers are very interested in Android as a tablet OS, only 52 percent are very interested in one of the leading Android tablet devices today, the Samsung Galaxy Tab. Further down the list, only 44 percent are very interested in the Motorola Xoom and 31 percent in the upcoming HTC Flyer. Smaller players (Acer, Archos, etc.) register minimal interest.”

Microsoft beat out RIM for third on the list. A total of 29 percent of developers showed interest in Microsoft, while 27 percent showed interest in RIM.