Vintage-45 is a meticulous simulation of the Hewlett-Packard's HP-45 scientific hand-held calculator fromIt offers a photo-realistic design based on the original device, animated keys with adjustable feedback, and all functions of the HP-45 faithfully replicated. Users can enjoy the nostalgia of the "secret" stopwatch feature and choose between full-speed or simulated speed for a genuine experience.

The app allows for correcting number entries by swiping across the display, supports cut/copy/paste functions, and offers additional conversions like Celsius to Fahrenheit, and more. For further guidance, users can double-tap the display to view the stack and memory registers, and tap for basic hints. Visit the developer's homepage for a manual and additional information.