TraderTest.org is not directly owned, nor controlled, by any trading firm. The tests provided do not represent all possible different tests out there but should cover the basics.
TraderTest.org does its best to post your resume at all the listed trading firms. This is on a best-effort basis and delivery cannot be guaranteed.
TraderTest.org's tests might not represent "real" (numeric) tests as you might get at a trading firm. Passing this test does obviously not guarantee passing a real numeric test.