During the first day of TwitchCon today, the live-streaming platform company owned by Amazon announced a full-featured Twitch App is coming to PS3, PS4, PS Vita and PS TV.
So far, the Twitch feature incorporated into the PlayStation 4 has only allowed gamers to stream gameplay and replay videos of only PlayStation 4 games. The newest app, to be released later this Fall, will allow gamers to watch live-streaming from PCs and other platforms, and use full chat features, including the emoticons.
The PlayStation 4 version will be released in October, with the other PlayStation versions to follow.
[Source]: Twitch: TwitchCon 2015 – Twitch Keynote; TwitchCon 2015 Keynote: Product Round-Up.