Detects and shows (XL, LG, MD, SM, Col) values depending on the window width.
A small icon will show up indicating the current viewport code. When rescalating the window, the icon will stay visible all the time to give you the exact Bootstrap 4 resolution you're using in that moment. You can easily move it to place the indicator in the position that best suits for you. The position will be saved and kept for future website loads. The icon will only show up whenever a Bootstrap 4 website is loaded, if not it won't be shown to prevent confussion.