Alarm Clock of Justice
is the tool that can warn you of the advent of your important appointment. For this, it offers several types of alarms/actions to choose from.
This includes playing a sound, the execution of a program or opening a document. You can use an audio or video file stored on your computer and adjust the volume to your preference. If you have an internet connection in your computer, Alarm Clock of Justice is also able to open a web address that allows you to use an online video as an alarm.