A recent study on U.S.-based mobile developers reveals that 53% of developers surveyed for the report build applications for the Apple iPhone OS.

Conducted by iGR, a market strategy consultancy that primarily concentrates on the mobile industry, the study asked developer participants a slate of questions about preferred platforms utilized in developing applications and software and which they will most heavily depend upon during the next year.

The iPhone’s operating system was the winner, hands down.

iGR, however, also probed devs in hopes of discovering which OEMs provided the best support, the types of applications they were developing and which devices, including tablets, they planned to support.

Apart from the iPhone OS, other popular platforms included RIM BlackBerry OS, and Android and Microsoft Windows Mobile 6.5. The findings of this recent survey stand in stark contract to the results of iGR’s similar 2009 survey which showed that Windows Mobile was the most utilized and popular OS by leaps and bounds.

“With each new feature and capability added to smartphone OSes, competition in the space continues to heat up,” said Matthew Vartabedian, research vice president of iGR. “Providing a solid developer experience and the ability for developers to generate revenue and profits off of the platforms is a key aspect of that competition.”

According to iGR, When asked to list five key factors when choosing a mobile platform, a majority of the developers surveyed said that multi-touch is “important” or “essential” to application development.