Yahoo has launched a new standalone iPhone weather app called Yahoo! Weather, along with an upgraded version of its Yahoo! Mail app that brings the native mail app experience to the iPad. The weather app is by far the more interesting development, receiving praise from many reviewers and users. The Verge reports that Yahoo is attempting to get a halo effect from apps like Yahoo! Weather, hoping users will try one product and love that one so much that they'll begin using other Yahoo services. "Marissa describes it as a chain reaction," said Adam Cahan, who leads mobile products at Yahoo, in an interview with The Verge. "I would love for you to use all 12 or 15 experiences that we're going to build for. You probably won't. But if
