Reactions allow you to use emojis to respond to a message in a more dynamic and expressive way. Reactions are designed to be unobtrusive. When you react to a message, members of the conversation do not receive a notification and their unread badge does not change.
To react to a message, long-press the message and tap one of the suggested reactions, or tap the emoji selector to choose your own.
If another member of the conversation has already reacted to a message, you can pile on with the same reaction by clicking on that reaction below the message or choose a new reaction with the + button that appears below the message (once at least one reaction has been made).
To see who’s used which reaction, long-press the reaction. The reaction you’ve used will be highlighted. If you want to remove a reaction you’ve used, just tap it again.
Up to 20 distinct reactions can be made per message, and each reaction can be used up to 99 times.