L2PVPEnchancer

L2PVPEnchancer is able to detect if Lineage II® is the currently active window and automatically enables the program while you are in game.

Though, you can choose to manually activate the program.
L2PVPEnchancer warns you about the current program state with ballons in the notification area (usually at the bottom right corner of your screen).
If you play in fullscreen these ballons might not be visible, though notifications sounds can be enabled in the configuration.