Digital Slide Rule brings back the classic calculating tool's elegance to your iPhone. This program replicates various types of slide rules including straight, circular, spiral, and cylindrical ones. With dozens of scales and modern features like color options and numeric displays, it offers a nostalgic yet functional experience. Despite being processor-intensive, the efficiency is notable, though patience may be required during certain functions due to the intricate details. Designed for large-format devices, the 30-loop spiral slide rule offers a unique visual experience, converting between bitmap and vector images seamlessly.

Program features like pinch/zoom and image rotation enhance user interaction, while a slide show of antique slide rules adds historical charm. Developed in 2016 with over 30 years of programming expertise, this tool is a tribute to the author's passion for numbers and the invaluable contribution of the Oughtred Society.