Among the nearly 50 apps in the "WebApps" group are apps for Southwest Airlines, the Food Network, 1-800 Flowers, TMZ, Orbitz, J.Crew, and CarMax.
The WebApps team is part of the Windows Store team, I hear. The WebApps team is different from the Microsoft Publisher Account, which is the team that makes available official Microsoft apps for Windows Phone.
I asked Microsoft what the WebApps team is doing and why. A spokesperson sent me the following statement:
"We are helping people access great mobile experiences on Windows Phone by creating pinnable Web Apps that show up in the app list. These are not a replacement for native apps. In most cases we hope that usage of the Web App will encourage the ISV to publish its own native app."
It looks like WebApps are yet another way Microsoft is hoping to encourage developers to build more brand-name, popular Windows Phone apps. I'm not against this tactic. On my Surface RT, I have nearly as many pinned Web sites on my Start screen as I do native apps. Sometimes, I've found a Web app to be as good, if not better, than the native app (example: New York Times).
As of mid-2013, there were approximately 160,000 apps in the Windows Phone store. The up-to-date tally is approximately 175,000, according to Microsoft.
Update: Some developers have asked whether Microsoft is violating its own app-development policies for Windows Phone with these WebApps. Requirement 2.10, in particular, specifies a Windows Phone app must do more than just launch a Web page. Microsoft isn't commenting on this question, but I believe these apps are rendering content within the app, not simply doing screen scraping of a Web site. So that may be Microsoft's "out" in this case.