I see many apps that look like web sites. These often feel the need to brand themselves with a logo and company name in the title bar. Or they present the company logo in a splash screen.
An app is not a web site. Apps are small focussed pieces of software. They live on a mobile device, and in that environment they act in a more personal and intimate role. The icon alone should brand the app. Making the conscious decision to launch an app you know what you are looking at.
Here’s a quote from the HIG:
Incorporate a brand’s assets in a refined, unobtrusive way. People use your app to get things done or be entertained; they don’t want to feel as if they’re being forced to watch an advertisement. For the best user experience, you want to quietly remind users of the brand identity through your choice of font, color, and imagery.