From the Numberscope landing page, you can access the visualization tool itself with either of the buttons mentioning "the 'Scope." (There's one in the top navigation bar and one right in the center of the page for convenience.) That will bring you to:
{! ../src/views/Scope.vue extract: { start: ''} !}
If Numberscope experiences an error, you might see an alert with the error message. If you see one that does not resolve upon reloading the page and trying again, please email the address shown with the error message.