THIS MOD IS DISCONTINUED AND WILL NOT BE SUPPORTED.
Author/owner has vanished, these accounts are maintained by Minecraft Mod Development.
Life Guage is a mod that displays the current health of a mob. If the mod isn't installed on the server, potion effects will not be visible. It's not required to be installed on the server, though. A server can also disable the mod for all the users connecting. 
You can see the current hearts on the name tag and the total hearts on the black bar. 
A name tag is always preferred over the normal entity name.
