When you write a problem, in the application, and you click solve, the application solves the problem. After solving it, you can click “Show steps” button. Then the steps and sub-steps of the problem are shown, and each of the steps has the description of that actual step.
In the right part of the step, you have the “highlight” icon (which is the letter i in a circle). If you click on the icon the app shows the difference, or the actual operation that is done, from the previous step to the actual step, with highlighting the actual part of the step.
When you click “Show steps” the application solves the problem, step by step, and shows the solving process with animation (if the animation is enabled in the settings page). You also can choose the animation speed, in the settings page.