What are some alternatives?
When comparing Slackmojis and Emoji Best, you can also consider the following products
Emoji Packs - Import emoji packs into your Slack and other chat apps
My Slack Emoji - Turn your team photos into Slack emoji's
Slack Emoji Reactions - Respond to any message with an emoji! 🎉😻🙌
Cult of the Party Parrot - Add dozens of Party Parrot emojis to Slack
Discord Emoji - Iconfinder, but for emoji.
AnimojiStudio - Make Animoji videos with unlimited duration