iPhone owners who pick up an iPad are often surprised to find that, while many things about iOS are the same, the built-in apps are not. Apple's Weather, Stocks, Calculator, Compass, Phone, and Voice Memo apps, all front-and-center on the iPhone, are nowhere to be found on the iPad Air or iPad mini. The why - that Apple perhaps didn't feel the interfaces scaled well to the big screen, or simply didn't think they were as absolutely necessary on a tablet as they are on a phone - doesn't really matter. What does matter is that the App Store has us more than covered with several excellent weather, calculator, stock, and voice memo apps for iPad to choose from. Which ones are the very best, however, and more importantly, the best for you?