Yes, Twitch is getting it’s own standalone app very soon. This app is not really new as it is a rebranding of it’s old Curse chat desktop app – which acquired by Twitch last year and turns into an official Twitch product.
This will be the same as the old Curse desktop app but with enhanced futures and focused more around the social aspect of Twitch (aka Pulse) allowing streamers to directly interact with their fans, share status updates and news just like Facebook. Twitch also plans to sell video games from it’s own download store.
You can try out the beta on 16th of March and the full app are expected to launch in Spring.