Mobile Walgreens’ mobile check-ins offer coupons, promos and value Customers who check in at one of the drugstore chain’s 8,000 locations through Facebook or Foursquare get messages directing them to products, offering coupons, or informing them of donations. By Matt WilsonFeb. 22, 2012 SHARE To read the full story, log in. Become a Ragan Insider member to read this article and all other archived content. Sign up today Already a member? Log in here. Learn more about Ragan Insider.