What's the first thing you think of when you read "Damage indication"?
That's right: health bars!

Entities will now have a healthbar displayed as their custom name, devided in two sections: (alive/maxHP)
The colors of these sections can be modified in the config, but are by default:

• Percentage alive (0, 255, 0)
• Percentage unalived (100, 100, 100)

The duration to which the healthbar is displayed, is customizable in the config as well (in seconds).
Example: '7'
However, note that this value needs to be between 1 and 10 seconds.

ps: Moved the open-source code to a new repository on github.