Khan Academy

https://www.khanacademy.org/

 Khan Academy is on a mission to give a free, world-class education to anyone, anywhere. Their personalized learning resources are available for all ages and most of the science subjects, including Mathematics. An excellent website for self-learner.

Desmos

https://www.desmos.com/

An online graphing calculator that students can use for free. You should visit Desmos whenever you need to draw a graph. Includes a teacher-centric activity builder for creating digital math activities.

GeoGebra

https://www.geogebra.org/

 A powerful online software for geometry, functions, algebra, calculus, statistics and 3-D math. Includes practice sheets.

Derivative Calculator

https://www.derivative-calculator.net/

Integral Calculator

https://www.integral-calculator.com/

 A powerful online calculator for differentiation and Integration. M1 and M2 students will find it extremely useful when they start their calculus studies.