A function management tool detects a user selection to drag and drop a particular selectable button from a first interface of the management tool to a second interface of an instance of a running application of multiple existing applications accessible at a computer system, wherein the management tool runs separately from the plurality of existing applications, wherein a separate pre-designated function is associated with each selectable button. Responsive to the management tool detecting the user select the dragged and dropped selectable button from within the second interface of the instance of the running application of the plurality of existing applications, the management tool controls the instance of the running application of the plurality of existing applications according to a particular pre-designated function of the dragged and dropped selectable button.