A very helpful feature would be an auto-suggestion of emoji based on the current written text. This could work very similarly to the auto-suggesting of hashtags perhaps. I'm thinking along the lines, too, of what SwiftKey does with their keyboard.
I think this could be very effective in cutting down the time users spend in going back-and-forth between the application in which they're trying to post from and going onto our site in order to reconfigure our /customize emoji settings→ and then back to their post to refresh and have to redo their post.
Customer support service by UserEcho