Greenshot is a free and open-source screenshot program for Microsoft Windows.
Any Greenshot plugin can contain persistence, the simplest being the "External command plugin" which uses command line; Modify the "Greenshot.ini" file in "%AppData%\Greenshot\", add an "[ExternalCommand]" configuration, add a new name to the "Commands" parameter, add the payload in the "Commandline.<name>" and "Argument.<name>", add the name to the "Destinations" parameter. Alternatively, from GUI, open "Preferences -> Plugins -> External command Plugin -> Configure", add the payload in the "Command" and "Argument" parameters, open "Preferences -> Destination" and enable the new external command.
Usecase: Establishing persistence on a Windows host