Well All are know I Phone is I Phone.We can't compare I Phone with Nokia,Not Even Any Other Brand.I Phone Mobile App Developers Are Just Awesome.

Simple. I'm thinking of something like OpenGL, iirc.

Developers can mitigate their risk by using multi-platform tools and approaches. Ideaworks Labs licences Airplay SDK, probably the most advanced multi-platform apps development solution on the market:
http://www.airplaysdk.com

"Cross platform" has negative connotations for many developers, as for some it suggests a lowest-common-denominator approach, typified by the legacy of J2ME.

However, the Airplay approach is to use a toolset that allows you to target iOS, Android, Symbian, Windows Mobile, webOS, Bada and Brew; your porting budget reduces enormously, so you have more time/money to spend optimising the user experience for the key form factors and hero devices. We like to think of this as "multi-platform" rather than "cross-platform".