A matrix determinant calculator app is a tool that allows users to calculate the determinant of a square matrix of any size. The app accepts an input matrix of any size, and then uses mathematical algorithms to calculate the determinant of that matrix.

The app may have a user-friendly interface that allows users to input the matrix in a variety of formats, such as manually typing in the matrix entries.

The determinants of following matrices are available:

- 2x2 matrices
- 3x3 matrices
- NxN matrices - Any size you want to add

Once the user inputs the matrix, the app uses algorithms such as Gaussian elimination, cofactor expansion, or LU decomposition to calculate the determinant. The result is then displayed to the user in a clear and easy-to-read format, along with any necessary steps or explanations of the calculations.

Overall, a matrix determinant calculator app is a useful tool for anyone working with matrices in mathematics, science, engineering, or other fields where linear algebra is used.