A calculator is undoubtedly a good thing, but with a calculator, you won't be able to plot a graph, calculate a quadratic equation (if you don't know the formulas), solve fractions, perform operations with matrices, etc. The iResolution program will come to the rescue, which will not only show the correct result, but also display all the actions taken to achieve the result. There are 90 calculators in the program. 
After starting the program, you will see the main screen, which contains the categories of 'fixers'. Categories in the program:
- Converters
- Number theory
- Fractions
- Equations
- Combinatorics
- Vectors
- Matrices
- Geometry
- Area
- Perimeter
- Volume
- Surface area
- Charts
Within each category, you will find corresponding subcategories where you can perform calculations and find detailed reference material on the topic. Special attention should be paid to the fact that the program supports charting. In iResolution, you can specify one or more functions, construction area and display parameters. After that, you can see the finished result.
Let's consider an example of calculating a quadratic equation.
To do this, go to Equations – Square. Find a detailed reference material on quadratic equations here. To solve the equations, scroll down the page and look for 'To solve a quadratic equation'. Here you need to enter the coefficients of the quadratic equation. For example, we will have the following coefficients: a = 1; b = (-3); c = 1. 
After you have entered the values, click the Solve Equation button. Below the program will give the result. 
In the program, you can find help on how to use the program correctly. It is located in the Help – Help section. 
This program for iPhone will be useful primarily for schoolchildren or students. But we do not recommend that you fully rely on the application, because it is forbidden to use phones on the GIA and USE, it is better to learn all the formulas by heart. The price is 66 rubles.