Processing is based on Java. If Apple accepts Java applications (not sure it does), then it can accept Processing applications.

I am almost certain the answer is no. I know that iPhone does not support Java and I believe iPad does not either but I do not own an iPad.

Also, he's lambasted, and consequently, quickened the demise of Flash plugin too early! 
Even today, HTML5 is still behind Flash performance and features. And that's gonna take awhile. 

I was speaking about Mac App Store

We understood that, that's why I mentioned Java, it is easier to search in the store rules than specifically Processing...
And while I know that Java was not running on portable Apple devices (not sure of current status, that's why you have to search yourself, unless somebody has direct experience of it), it works on Mac devices, so the status is even more fuzzy.

Ok thanks. I think I'll write directly to apple and I'll let you know if they answer :)

The answer is probably already in the Store site in the section for developers...