Twitter now supports 1100+ emoji, including choices such as love/heart symbols, country flags, hand gestures and smiley faces. Just click on the following icons to copy, and then paste them into Twitter. Don’t worry if you see an empty square, because Twitter will convert this into a colorful icon once you post the Tweet. Your followers will see the colorful emoticons. Emoji work on all computers and smartphones.
This will automatically collect your most recent and frequently used icons.