Samsung Electronics Co., the world's largest mobile phonemaker, on Friday released its latest Galaxy S5 smartphone and wearables in 125 countries around the world as it battles squeezed profits and challenges to its top market position. Such simultaneous launch is the biggest of its kind for any of its previous product. The previous generation S4, the best selling android phone ever, started selling in 60 countries, and its Note 3 was first released in 58 at the outset.