scientific calculator -- 6

I am looking for a freelancer who can develop a scientific calculator with the following functions:
- Basic arithmetic operations (plus, minus, divide)
- Trigonometric functions
- Logarithmic functions
- Square root
- Root
- Percent
- Ans
- Converter for length and volume
- Data

I would prefer a minimalistic and clean design for the calculator.

As for the platforms, I am open to suggestions and would like the calculator to be available on both web and mobile (Android/iOS) platforms.