The React Sticky[State] Component makes native position:sticky statefull and polyfills the missing sticky browser feature.
todays browser do not all support the position:sticky feature (which by the way is beeing used (polyfilled) on pretty much every site you visit) - moreover the native supported feature itself comes without a readable state. something like a:hover => div:sticky to add different styles to the element in its sticky state - or to read the state if needed in javacript.
unlike almost all polyfills you can find in the wild StickyState is high perfomant. the calculations are reduced to a minimum by persisting several attributes.