May take more than one application, but definitely helps reduce the visibility of scratches.
I bought this to try to fix some scratches on my Apple Watch.  The initial scratch I was trying to fix wasn't super deep, so I thought this stuff would probably do the trick.  I was disappointed that it didn't seem to do much, it made it less noticeable (didn't look white any more, but could still see the scratch if you looked closely), but didn't help as much as I had hoped.  I planned on giving It 3 stars.  A few weeks later, I put a very noticeable scuff in the screen, so I decided to try it again.  I just rubbed the stuff over about 1/2 of the screen, wherever I could see any tiny scratches and scuffs.  This time, I had much better results, and even the initial scratch I had tried to fix looks even better, I can now only notice it if am really trying.  I'm going to give it 4 stars, since its still not perfect, but it definitely helps make scratches a lot less noticeable.  My main take away is if a scratch isn't fixed to your satisfaction, it may take more than one application.  If I get any more scuffs, I'll probably just go over the entire screen again.
Rating: 4 stars