iRemind lets you set a fixed time, then it calls for attention using customizable notifications, screen messages, by saying "Hello!" (or whatever you wish), or by playing a piece of music or a couple of beeps. It can run several reminders, each at its set time, and skipping one or more days of the week. Reminders may be set in the New or Edit window (clicking the relevant button).
In the New/Edit window, users can choose whether to be reminded by notification, a screen-message or by voice (or both), or by playing a piece of music. Screen and voice messages are customizable; voice messages can be in any of several languages, provided you have the corresponding voice installed; as for music, the user can select her/his own audio-file.
iRemind can also launch a user-selected application at a given time.