Touch screens supporting different inputs such as `Tap’, `Dwell’, `Double Tap’ and `Force Press' are omnipresent in modern devices and yet this variety of interaction opportunities is rarely communicated to the user. Without visual signifiers, these potentially useful inputs remain unknown or underutilised. We propose a design space of visual signifier characteristics that may impact the perception of in-place one finger inputs. We generated 36 designs and investigated their perception in an online survey (N=32) and an interactive experiment (N=24). The results suggest that visual signifiers increase the perception of input possibilities beyond `Tap’, and reduce perceived mental effort for participants, who also prefer added visual signifiers over a baseline. Our work informs how future touch-based interfaces could be designed to better communicate in-place single finger input possibilities.