Is it worth the cost?
isitworththecost.com/A simple calculator for decisions
Omni Calculator
omnicalculator.com/Omni Calculator solves 541 problems anywhere from finance and business to health. It’s so fast and easy you won’t want to do the math again!
Colormind - the smart color palette generator
colormind.io/Colormind is a deep learning AI that knows color theory. It can generate color palettes from scratch, or it can take your input and intelligently fill in the blanks.
Matrix Multiplication
matrixmultiplication.xyz/An interactive matrix multiplication calculator for educational purposes
Calca - The Text Editor that Loves Math
calca.io/Calca is an advanced symbolic calculator for iOS, OS X, and Windows that's as easy to use as a text editor.