touch screen interface on 360 content.

https://developer.mozilla.org/en-US/docs/Web/API/Touch_events 
https://www.w3schools.com/jsref/obj_touchevent.asp 

Checking for an actual Storyline sample now.

Basically this is the workflow.
Add this in a Slide Trigger that gets executes on timeline start.
/*
As Storyline doesnot support all mouseEvents default we are adding that here
*/
var wrapper = document.querySelector("#wrapper");
//var rotateButton = document.querySelector("[data-acc-text='rotateButton']");


if (wrapper.addEventListener)
{
    // IE9, Chrome, Safari, Opera
    wrapper.addEventListener("mousedown", MouseDownHandler, false);
    wrapper.addEventListener("mouseup", MouseUpHandler, false);

    // Firefox
    wrapper.addEventListener("DOMMouseDown", MouseDownHandler, false);
    wrapper.addEventListener("DOMMouseUp", MouseUpHandler, false);
}
// IE 6/7/8
else
{
    wrapper.attachEvent("onmousedown", MouseDownHandler);
    wrapper.attachEvent("onmouseup", MouseUpHandler);
}

Now your complete Storyline will act on touch.
Use the handlers to act upon the touches.

function TouchStartHandler(event) {
    var touches = event.changedTouches;
}
function TouchEndHandler(event) {
    var touches = event.changedTouches;
}

Do check this article to learn more about the results you can get from the touchevents. Remember...touching can be done with multiple fingers, so you get more info then with a mouseclick.

https://jenkov.com/tutorials/responsive-mobile-friendly-web-design/touch-events-in-javascript.html