As developers at the top end of the residential market know all too well, amenities can often make the difference in courting the small demographic that can afford the most extravagant residences. The result is an arms race among building owners to provide truly unique services and offerings — in this day and age that translates to the liberal use of technology. Property Markets Group, for example, is testing out a smartphone app for residents to access building and concierge services at its recently opened Echo Brickell condo tower in Miami, The Real Deal reports.     Read the article………………..