It will be so useful to know when a Vertical or Horizontal container has scrolled to a certain point. For example, until a Vertical container has scrolled to the bottom I want an arrow facing down below my container to let the user know that there is more content. When the user scrolls to the bottom, I want to hide the arrow. If they scroll up again, the arrow should appear again. This would also be very useful to ensure that a user has read or scrolled the full content of Terms and Conditons etc. before being allowed to click next.