I could be mistaken, but, the LG G5 smartphone is not ANT+ compatible. You can download ANT+ apps all you want and it still will not turn your LG phone into an ANT+ compatible device. You may have to root the device, but it will be very buggy and unreliable. Check out the ANT+ directory if your device is compatible here:
https://www.thisisant.com/directory/...115%7C118/~/~/