Stefan Kaczmarek is a software Engineer with over 20 years of experience specializing in mobile applications, large-scale software systems, project management, network protocols, encryption algorithms, and audio/video codecs. He has experience developing iOS software from webcams to fitness to education to point of sale. Stefan is also the author of Swift 4 For Absolute Beginners and Objective-C For Absolute Beginners. Brad Lees has more than a decade of experience in application development and server management. He has specialized in creating and initiating software programs in real-estate development systems and financial institutions. His career has been highlighted by his positions as information systems manager at The Lyle Anderson Company, product development manager for Smarsh, vice president of application development for iNation, and IT manager at The Orcutt/Winslow Partnership, the largest architectural firm in Arizona. A graduate of Arizona State University, Brad and his wife, Natalie, reside in Phoenix with their five children.