vue-check-view
Simple vue plugin that checks element position on screen (viewport) and adds classes to element. ES5 supported.
jquery-visible
Quickly check if an element is within the browsers visible viewport, regardless of scroll position. If a user can see this element, the function will return true.
ngx-position
A set of angular directives that allow to absolute align elements according to another one's position, as well as another set that allow to quickly apply CSS positioning properties.