RightGIF - Less noise, better GIFs. A better /giphy for Slack.
Slackmojis - A directory of the best custom slack emojis
Firesong - Giphy for Music in Slack w/ Emoji Search
Discord Emoji - Iconfinder, but for emoji.
Slack Meme Bot - Spice up your team conversations with memes
Emoji Builder - Create your own emoji in no time 💨