Scientific Calculator RedCrab app for iPhone and iPad
As a fully functioning calculator, it basically summarizes the common mathematical operations. In addition to the commonly used addition, subtraction, multiplication, and division(including brackets), there are also trigonometric function operations such as sine and cosine, the log operations, root operation and operator (% is modulus mod) and so on. It also supports the revision of history (clicking on the "history" button to display all of the historical results ).