How do great moves work?

No im on the app on my phone

Apps still have the older Game Report product 

So i need to be on pc to see great moves ?

That is correct.

Okay thnk you

great moves are the best move that puts your rivals at a significant disadvantage but not that hard to find capturing a hanging queen is an example of a great move another example of a great move is pinning a queen. great moves maintain the evaluation however best moves might lower it slightly imagine you had choice moving a knight out of danger, winning a exchange or capturing a hanging queen the ladder is the great move. if you don't know what the ladder means look it up.

on my chromebook great moves show up and I don't think it's a PC

It's a full browser, not mobile app

Great moves fall into a couple of categories.

1. A move that punishes a blunder very well. For example, your opponent hangs their queen and you take it with a piece that hasn't moved yet.

2. The only good move in a position. For example, if your opponent is about to play checkmate, and you manage to find a move that forks both of the pieces and protects the checkmate at the same time. Making the correct follow-up move to a brilliant (!!) move may also receive a !.

3. A hard-to-find move (or set of moves) that doesn't require a sacrifice. If it did, it would likely be brilliant (!!).

4. A sacrificing capture that doesn't outright win the game unless your opponent takes it can sometimes get a ! instead of !!. Generally, this occurs only if you already had quite the advantage.

5. A game-winning sacrifice in a position where you already had a considerable advantage. The advantage of either player dictates how their moves are considered; if the game was pretty close until that point, it would get a brilliant. Additionally, if the sacrifice is pretty obvious, this might also cause it to only get a !.