This is an open-source programmable scientific calculator with functionalities of 2D-plotting, Solving Quartic(or lower) functions, Newtons method, dealing with Complex numbers.
"People who dont need Scientific Calculator" will also feel insanely useful because the calculator intuitively shows you the ways you calculate!
Give it a try!
Source code :
https://github.com/CANDY-HOUSE/Scientific_Calculator_Plotter