Yes, it's legit! My FIL is a doctor who retired and moved to the Philippines about 10 years ago. Last year we found out about that website and checked our name. Well, his name came up. It turned out he didn't cash in all his money sources before he left, and he had 3 big checks sent to him(about $18,000 total!!!) after filing the form.
Check your name, you never know.