Apple, Google, Samsung vie to bring health apps to wearables

A model presents a Samsung Galaxy Gear smartwatch after its launch at the IFA consumer electronics fair in Berlin

For decades, medical technology firms have searched for ways to let diabetics check blood sugar easily, with scant success. Now, the world's largest mobile technology firms are getting in on the act.

Apple Inc. (AAPL.O), Samsung Electronics Co (005930.KS) and Google Inc. (GOOG.O), searching for applications that could turn nascent wearable technology like smart watches and bracelets from curiosities into must-have items, have all set their sites on monitoring blood sugar, several people familiar with the plans say.