The Office Phone Manager application is built using Django, a Python web framework. It allows office managers to easily manage and customize their phone systems by creating configurations for specific phone numbers, schedules, and actions. The application interacts with Twilio, a cloud communication platform, to handle incoming calls and return TwiML responses. The application's data structure consists of Configuration, Schedule, Day, Action, Parameter, and TwilioNumber models, which are linked together through foreign keys. The application has a single endpoint that handles incoming Twilio requests, checks if the configuration is active, and returns either the standard action or the out-of-office action based on the schedule's availability. To deploy the application, users will need to set up a virtual environment, install dependencies, and host it on Heroku.