Apple appeared in The Annoying Orange, where he was one of Orange's friends.
In the episode, Apple was first seen being annoyed by Orange with him constantly saying, "Hey, Apple! Hey Apple! Apple! Hey!". In the end, he got sliced in pieces by Daneboe. Then, Orange went to talk to Pear instead.
He was voiced by Daneboe himself.
* Even though he only appears in one episode, he is mentioned by Orange many times during the series.