Took me awhile to realize it was keying off the last word I had typed, "bug", and was offering emoticons at the quick. Okay that's kinda fun I suppose. I'll toss some :bugs: in with my bugs.
iOS 10 offers this in at least its text messages. Any word for which it thinks there is an appropriate emoji, it highlights in orange. Tap the word and it is replaced by the graphic.
How far can this go I wonder. I started with a blank line, and noticed only "I" and "If" were suggested. ok go with "if". I let it ride until it repeated a word.
This was a game in which a few of us on this site engaged in awhile back, using iPhones or iPads. In Messages type one letter, make a choice of words from the three offered; Messages then auto-suggests three more, choose, etc.
We posted some of the "poetry" that resulted.