This is time control software that lets a user use an application (a game maybe) for a given time or how long (as a master overall control) the user can be logged in.
Parental control software makes it possible to make sure children use a particular game for a given time. As an alternate, you could control how long, overall, a system could be used by them. Thus the children can be prevented from spending unduly log time on the Internet or on a game. The control to this application that can set/reset these time limits can only be accessed through a master password. The application, once set, cannot be detected by the user on the machine. In a corporate setting, you could get accurate time-sheets that show what applications were used and for how long on a given machine. Their attendance also could be verified easily.
All activities of users will be recorded on log files. The Time sheriff will log the user out based on the restrictions imposed by you. Besides company use, these could be useful to service providers. One straight application could be in an Internet cafe where individual users could be set different times and specific applications. The logs will tell you in a report format you desire, who, when, and for how long have used your PC for which applications and how long. The interface makes it all quite easy and intuitive for setting up and then obtaining the details later. You will need a little time to get familiar with the tool but it is easy enough. Rules set up can be for groups or individual users.