You might want to also do some research into the app store's for your respective targets. I might be wrong on this but from my understanding apple's app store only allows Objective-C written apps while Google's play store prefer's maybe even requires Java written apps.

Beyond that cross platform hassle's always occur, you will need to gain access to the device specific rendering and input API's either building your own mobile engine of sorts or using something pre built. There are many options for this however most are Java or HTML5 / JS related. I'm sorry that I'm not answering your questions but I would suggest that you research in to what technologies are available for cross platform development and what will best suit you and not focus on the fact that you want to use C++.

From just some quick google'ing it looks like OpenGL ES is mainly an iOS thing, I can't find any reference of it's usage on android devices. Android does use open gl and here is a reference page that should get you started (directly from the android developers network)

http://developer.android.com/guide/topics/graphics/opengl.html

Here is the apple reference for using OpenGL on the iOS platform (which does make particular note of the ES flavor)

http://developer.apple.com/library/ios/#documentation/3DDrawing/Conceptual/OpenGLES_ProgrammingGuide/Introduction/Introduction.html

Box2D on iOS...

http://www.iforce2d.net/b2dtut/setup-ios

Port of Box2D for android (it's java...)

http://code.google.com/p/androidbox2d/

If nothing else these sites should get you started understanding the differences between the implementations of these technologies on the two different platforms.

I might be wrong on this but from my understanding apple's app store only allows Objective-C written apps while Google's play store prefer's maybe even requires Java written apps.

Neither of those is this case. C++ is a viable route for both Android and iOS game development (though less so for app development, since the UI frameworks are in different languages)

my understanding is (not sure if this is 100% right) - Both Google and Apple says they support openGL ES and I believe my game should run properly if i am 100% compliant with openGL ES.

Two items you may wish to consider (or ignore till later):

• Both platforms support OpenGL ES, but you still have to write quite a lot of platform-specific code to actually obtain an OpenGL ES context, not to mention handling input, application lifecycle, and actually compiling for that platform in the first place.
• OpenGL ES support varies from device to device, even those running the same OS. You need to choose between fixed-function (ES 1.x) and programmable shaders (ES 2.x) right off the bat. And even then, that basics should be entirely portable, but complex shader effects will often need tweaking for various driver/GPU combinations.

There is on gotcha I dont believe has been mentioned in this thread.

If you want to support OpenGL ES and in C++ only, on Android, that means 2.3 and higher devices only. That shouldn't be a huge deal, but still something to be aware of.

You will also find in Android that not 100% of the the Java APIs have been provided in C++, so you will find you will have to work around this on occasion. Generally though, these aren't the APIs you would need in your game.