This image is simply this mod's in-game icon.
This screenshot shows how the mod displays the amount of damage taken, along with the source of it (taking fall damage, in this case).
This screenshot shows how the mod displays how much health you regain, in the action bar, every time you do.
This screenshot shows how the mod displays an action bar message, every time the player's health has reached their maximum (the message disappears after a second).
This screenshot shows you how the mod displays an action bar message, for when the player has died (the message will disappear after a second).
This is a screenshot that shows how the mod displays the amount of Absorption HP lost (new update).
This screenshot shows how the mod displays an action bar message when you loose all of your Absorption HP.
This screenshot shows how the mod displays an action bar message when your Absorption health increases (when getting pot effects, e.t.c).
This screenshot shows how the mod displays an action bar message, when you loose all of your health (new update; the action bar message now includes the last damage source, when you loose all of your HP).
This screenshot shows how the mod displays an action bar message, when you loose all of your Absorption health (new update; the action bar message now includes the last damage source, when you loose all of your AHP).
A new update (yay!!!): This screenshot shows how the mod displays the estimated damage blocked, when blocking with a shield in your main-hand, or your off-hand (note that the blocking message only appears if your shield is not unbreakable).

This is a simple Fabric mod, that allows you to see your own health changes in the action bar.