Kill Tracker
A kill tracker is an external program used to keep track of the number of kills a player has achieved. They usually also track various other statistics, such as your deaths, duel wins, duel losses, etc. Commonly, kill trackers also have functionality allowing you to automatically say lines via chat when you die or get a kill, including various related information (eg "I just killed you Padawan, I have 99 kills.")
Kill Trackers often have various other functions, such as minimisers and media players. Notable examples are BobaFett's Ultra Utility and Jam's KT.
Controversy
Whilst Kill Trackers are quite popular, many find their automated speech to be too close to spam and find them greatly annoying, whilst others enjoy this feature. As a result of this, some servers either ban Kill Trackers, or require players to set them to silent mode.