By Julie Weed, The New York Times Company Employees returning to the office in the midst of the pandemic are bound to arrive with a new set of questions: What health precautions have been put in place? How crowded is the cafeteria? Which meeting rooms are available? How do visitors gain entry to the building? To ease their adjustment, a growing number of office managers are using mobile apps that offer the answers that workers seek. Building apps are designed to connect office tenants to maintenance, security and logistics systems and community-building programs.