Math Order of Operations Step by Step, developed by Digital D LLC, is an interactive Android app that simplifies the process of learning the order of operations in a math expression. The app teaches PEMDAS, which stands for Parentheses, Exponents, Multiplication/Division, Addition/Subtraction. It also covers other variations of PEMDAS such as BEDMAS, BODMAS, and BIDMAS.

The app offers two modes of interaction. In the first mode, you can type your own expressions or let the app generate them for you. The second mode is a multiple-choice option where you have to pick the right answer for each step. Additionally, you can go to the next, previous, first, or last step depending on your preference. The app also allows you to turn on or off sounds as per your liking.