You might not have to leave your cubicle at work or your couch at home to get that sore throat or nasty cough checked out. Walgreens is launching a virtual doctor visit feature on its mobile app, the company announced Monday. The nation's largest drugstore chain is teaming up with MDLive, a provider of virtual health services, to connect Walgreens customers with certified doctors via video chat on a smartphone, tablet or computer. The service is immediately available to residents of California and Michigan and will be rolled out in other states in the next few years.