Samsung just added a new support for Tizen SDK Wearable, it has now added support for Gear S, if you want to develop app for Gear S you can download the new Tizen SDK for wearable...
source:
http://www.downloadtizenapps.com/2014/09/download-tizen-sdk-for-wearable-beta3-1-0-0-with-support-for-gear-s.html
source:
http://www.downloadtizenapps.com/2014/09/download-tizen-sdk-for-wearable-beta3-1-0-0-with-support-for-gear-s.html