I have a suggestion for spectator mode. An option should be able for a spectator to track a certain player, instead of just the overall game. This would normally be disabled and thus kept the way it is now, but a table master could enable it on a per-table basis.
When enabled, any player with spectator mode enabled can select a player and view the game situation as if they were the player. For example, they would be able to view the cards in a player's hand, or have the chess board flipped to black if the player was playing as black in a chess game. I bring this suggestion up because it might make uno a more interesting spectator sport. The cards are played so quickly that it's impossible to keep up without knowledge of at least one person's hand of cards, making the only point of interest to be the scores at the end of each round. I bet a lot more people would watch uno games if they were able to see the cards held by a fan player. And of course, if you didn't want information leaks, you just leave the option disabled.

cool suggestion , this would actually be quite useful in battleship , as you can select a player and view his grid , because right now , there is no point in being a spectator in battleship.

Certainly agree! I've been always willing to take a look at hands of other players to see what have they got, not only at uno tables.

I dont agree with it cause if my friend join the table and be spectator he can tell me what another one has in hand

That's true, though if you think it may happen, the master could just disable the option.

yeah butif master is not fair player what can the other one do if he invites his friend to tell him what's in hand of other player

kick that player then. I think this could even work in the uno league matches even though the stakes are higher, if all the spectators agreed to keep quiet.

This could be very good when learning someone a new game

The idea isn't bad, but unfortunately it's not as easy as you may think to make it. I'll keep this suggestion somewhere, but won't be able to implement it very soon. Thank you anyway !

One day, i was playing backgammon with other player. I invited a frend of mine and then i replace myself by this other person. Of corse, i could see all the bord: with the empty squares and where were the tokens of the two players. It was useful because the other player was learning the game and it was eacy to help him, even if i wasn't playing.

for board games such as connect four , chess , reversi and backgammon , you can already see the grid and help someone who is learning and it is really cool.

I agree. I am using spectater mode for lurning strategies. So I am thinking that he is stupid but he may don't have that kard. It wil be extra in games like rami. And to see who is winning.