When I was in hs, a similar service did find some interesting outside scholarships. Eg, a good one for my grandfather being a vet of a wartime experience in certain areas. (But limited to certain colleges I wasn’t applyng to.)
And I suspect there are legit services today. But don’t throw money at one that advertises its successes in order to serve themselves, first and foremost, line their own pockets.
Be wary of manufactured stats. No one can guarantee you 15k in “found” college money. Start with a google search for ideas, from organizations that publish opportunities across the board, where you then vet and match yourself. And submit your own applications.
I told my kids to always watch for "Who’s driving the Mercedes.? It means, who’s making money off you, promising lush results that entice you.
Look on CC for merit award threads and suggestions. Run the Net Price Calculators (NPC) found on college websites.