Calculary

Do the same has a normal calculator and much more, with Calculary you have more options than a normal calculator.

Do the same has a normal calculator, solve complex math functions, get the derivative or integral of f(x) or even view a preview of how a function plot look like. Also you can solve your daily problems with a numerical method.

With Calculary you also can have a counter to have a record of the total of your purchases or the account in a restaurant, or even more things.

Calculary is an open source proyect, so if you're a programmer or just for the curiosity of how calculary works, you can see the source code here(https://github.com/jralvarenga/calculary), also, Calculary has integrated MathAPI, another open source proyect you can check here(try-mathapi.vercel.app/)