Notice the picture on the right has the problem and highlighted the term needing to be moved. The student then puts their finger on the number and moves it to the other side.
Once on the other side, a key pad comes up and asks the student to put in the correct operation.
Once they finish the problem, they get a congrats and stars.
If a student makes a mistake,the program tells them immediately and circles the error.
The linear equations can be one step or multiple steps but it always shows the completed steps and shows errors. I like this app and the best part of it, its free.