viewport-watcher-js-example.js

$('.viewportWatcherExampleTrigger').viewportWatcher(function() {
    // Element is in the Viewport Do Something
    $(this).find('.viewportWatcherExample').fadeIn('slow');
}, function() {
    // Element is out of the Viewport Do Other Thing
    let display = $(this).css('display');
    if (display != "none") {
        $(this).find('.viewportWatcherExample').fadeOut('fast');
    }
});