UPDATE: Samsung seems to have expanded its list of countries that won’t support stress or heart rate measurement feature. (See below)
Samsung first introduced its S Health app with the Galaxy S4 and though Samsung has updated the app with new features, for some reason, Samsung offered different versions of S Health for its devices. For instance, Galaxy S4’s S Health was stuck on v2.5 while the Galaxy Note 4’s S Health current version is v3.5. This prompted Samsung to create a separate app called Fitness with Gear that basically allowed the data from Gear devices to sync with the phone since Gear was unsupported with the older version of S Health.
As you can see from the screen shot above, Samsung has now retired their Fitness with Gear app and updated the S Health for devices like the Galaxy S4. The updated S Health is now v3.5.1 with a similar interface you’ll find on newer devices and Comfort Level now identified as Thermo-hygrometer. The app now syncs with Gear and other compatible devices has even included Sleep tracking but left out heart rate measurement and stress levels.
Although Samsung says heart rate measurement is missing only for users in Angola, we could not find the heart rate option in India as well.
Samsung should automatically update the app or you can manually go into the S Health settings to check for an update.