significant software

 Download the installer (as .ISO)

Replayer is a free media player for use during rehearsals with playback music. It’s main feature is fast navigation to predefined cue points in the playback media.
Visual functioning of Replayer
First, you create a compilation of tracks and cues once. Then, using Replayer and your laptop computer, you can rehearse any portion of your set with ease. For fast navigation, use the numeric keypad.

See the Leaflet for an overview, or the User Manual for detailed information. The project and the source code is on Github.

See also quirli, which is Replayer as a web app.