Yes, another username scanner, on purpose
Aliens Eye checks a username across a wide set of sites. The Consensus snapshot for this course put that coverage in the high hundreds. The licence is MIT. The project was still receiving pushes when this lesson was written. Both of those facts can change. Before you tell anyone the tool is "active" or quote a site count, look at the repository, not at this paragraph.
Feature-wise it will feel familiar if you have done Sherlock and Maigret. You feed it a handle. You get candidate profile URLs back. There is no special sensor hiding in the name. A username tool with a dramatic name still fetches pages and applies rules.
It is in the twelve because comparison is a skill, and beginners treat the tool with the biggest number as the winner. Analysts treat disagreement as a checklist. Aliens Eye is the sparring partner. You already have Sherlock. You may have Maigret and GoSearch. A third list is useful only if you do the reconciliation. If you only keep the longest list, you have learned shopping, not tradecraft.
Some blurbs in the wider ecosystem attach the word AI to tools in this family. If the README in front of you mentions a model, an agent, or a score, ignore it as evidence. A URL you can open is evidence. A paragraph the tool wrote about the URL is a summary of a page you should have opened. Summaries of pages you did not open are how fictional case files get their confident tone.
The point is not to marry a fourth username tool. The point is to catch the first three being incomplete, and to catch this one being confident.