Please do not install this app manually, it should be downloaded via Samsung gear manager app automatically.
App link- http://galxy.us/batteryWidget
This app gives information about your mobile phone battery.
Just add an widget to your gear watch and it will show the phone battery status.
This app is built by considering power efficiency, for both Gear watch & Android phone. So you could see the state of your charging phone from a distance, without draining your battery.