Scientific calculator

This scientific calculator has many advanced features, which are:
- Memory usage
- Interactive history of all equations
- Calculation with parentheses
- Unary operation
- Mathematical constants, such as: the numbers pi and e
- Percentage (%)
- Factorial
- Trigonometry functions, such as: sinus, cosine, tangent, logarithm, natural logarithm.
- Two screen orientations (landscape and portrait modes) with different look. Each one is designed for each orientation for better and convenient user experience