Desmos: Desmos is an online graphing calculator. Desmos has an online scientific calculator and an online graphing tool. Using the graphing tool, you can make different functions different colors to better understand the differences between them.
Mathematica: Mathematica is a program that can solve various mathematical computations. Using this program, you can solve a simple addition problem or a difficult integration problem. Mathematica is a good tool to use to visualize graph functions quicker than solving by hand. You can also create 3D graph curves. This program is helpful to both educators and students.
LaTeX: LaTeX is used to prepare documents. It is a great tool to use in mathematics as it allows you to type various functions and equations. You can edit, add images, use bold or italics, and add any math related symbol needed.