Hemithioindigo (HTI) is an emerging photoswitch with many advantageous properties compared to the commonly used photoswitches like azobenzenes, spiropyranes, or dithienylethenes. In this DIGEST the syntheses, physical and photophysical properties of HTI photoswitches and mechanistic explanations for the latter are reviewed. Emphasis will be placed on those distinct properties that render HTIs into unique phototools. Additionally, a broad variety of applications ranging from supramolecular to biological chemistry is presented to highlight the great potential of HTIs as upcoming, alternative photoswitches.