It has a catchy name, a nice design, and the right price tag—free. But is Kensington’s new Rise & Shine Clock & Weather app going to succeed at its apparent task: helping the company to sell its new $40 Nightstand Charging Dock for iPhone? Or is it the other way around: are users supposed to learn about and purchase the Dock first, then show up to the App Store to collect their free clock app? We learned about the Nightstand Charging…