Web Equation
webdemo.myscript.com/portal.html?locale=default
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
Write an equation in the yellow zone. After a short timeout (a second) the recognition will be launched and the result will be shown at the bottom of the page. You can clear the writing space by clicking on the garbage can icon in the top right corner of the yellow zone.