RungeBot is a Twitter and Mathstodon bot that tweets polynomial interpolations of functions using equidistant points and Chebyshev points to show Runge's phenomenon.
There's an explanation of what RungeBot does at mscroggs.co.uk/blog/57.
To get RungeBot to interpolate a function for you, tweet @RungeBot f(x)=[your function here] or toot @RungeBot@mathstodon.xyz f(x)=[your function here].
It will reply with a picture and it will tell you how bad Runge's phenomenon is for your function.
RungeBot uses my fork of the Equation package.