How to customize Facebook Messenger chat conversations on your iPhone or iPad
Additionally, you can change the default thumbs-up emoji to another one. Want a kissing emoji? Okay! Laughing emoticon? Should come in handy! A dancing lady one? Well, we can't imagine why you would want one of these to be available at a finger's tap away, but be our guest!
Last, you can set up a different nickname for each one of the Facebook peeps you're chatting with. Be careful, though - they'll be able to see the change, so custom names like "Annoying person #3" or "Smelly co-worker" will certainly do way more harm than good!