Swype does this too, although I never really use them, it is a cool feature.
Re:Android N developer preview 2 is out
by sardonicbryan on Thursday April 14, 2016 @12:08PM
(#11497842)
Swiftkey has this, and it really changed the game for me because it baked emoji discovery directly into my typing flow.
Everything else about LINE is terrible, but I'd love it if everyone just copied that particular interaction.