Thumbs Up
A thumbs-up gesture indicating approval.
In certain contexts, the use of the Thumbs Up emoji can be construed as being passive aggressive or sarcastic. Despite this possible use, it remains a popular means of quickly and earnestly expressing approval.
Thumbs Up was approved as part of Unicode 6.0 in 2010 under the name "Thumbs Up Sign" and added to Emoji 1.0 in 2015.