nRevenge

Currently not able to deliver updates or new features. Maybe check out https://www.curseforge.com/wow/addons/spy-classic which looks more mature and well developed (Check out Kill On Sight feature)

Put unfair gankers that killed you while you were fighting a mob on a list. When you see them again later, the addon will play a loud sound and prints a message to the chat.

You can add/remove players via context menu (Right-Click on the enemy) or use commands:

Either use /rev, /revenge or /gank and then the following commands:

/gank      - Prints all available commands

/gank {Name of the Player}     - Puts the name on the ganklist

/gank {Name of the Player} {Reason}    - Puts the name on the ganklist with the specified reason

/gank target    - Puts the name of the current target to the ganklist

/gank remove {Name of the Player}    - Removes the player from the list

/gank list    - Prints all names on the list to the chat, Only visible to the player

/gank export   - Creates a export frame with all names including reasons. Copy and Paste content to share lists

/gank import   - Creates a import frame. Paste a list exported from another user

/gank reset    - Clears the list