Why can't I find Gear app in Galaxy Apps?

I bought a Samsung Gear Fit 2 activity tracker from ebay. I would like to use the Gear app on my phone with it. I have a Samsung phone kitkat with Samsung Galaxy Apps installed. When I search for the Gear app it isn't found. Why can't I find it?

Also, I have an LG phone kitkat. On non-Samsung phones you are supposed to download the Gear app from Playstore which I did. When I try to pair the phone with my Fit using the Gear app, it says no devices found. Why can't it pair with my Fit?