Samsung Electronics Co., the world's largest maker of smartphones, unveiled its first wearable device that runs on its own mobile operating system Tizen at a trade show in Spain on Sunday, as it seeks to break its heavy reliance on Google Inc.'s Android software. The unveiling of the Samsung Gear 2 and Gear 2 Neo, Samsung's successors to the Galaxy Gear, also comes as the South Korean tech giant is struggling with a slowdown in its sales of high-end smartphones.