Num Lock Indicator software is officially released on September 19, 2012.
The software offers two Num Lock state indicators: Tray Icon and On-Screen Floating Text.
Notifications by sound are also available. Moreover, sound alerts can be different for On and Off states.
The product is distributed on the Try Before You Buy model with 30-day trial period. The license costs $9.95 per computer or user. There is a volume discount.