OLD Complex Numbers is a free Android app developed by Ivan Petuhov for math enthusiasts. This app is designed to help users perform complex number arithmetic with ease. The app has a simple and user-friendly interface that makes it easy to use for anyone who wants to learn complex number arithmetic.

The app allows users to perform basic operations such as addition, subtraction, multiplication, and division. It also includes advanced operations such as finding the conjugate and modulus of a complex number. The app also features a history tab that displays previous calculations for easy reference. Overall, the OLD Complex Numbers app is a useful tool for anyone who needs to perform complex number arithmetic quickly and easily.