My Gear Manager was downloaded and installed automatically during the set up process after unboxing my watch.
I have an Icon on my phone that says 'Galaxy App store', (not 'Samsung App store). I just did a quick search there and there is only one Samsung Gear Manager. -- (See attached image below).
It is the Galaxy app store I mean by Samsung. I have two incidents of both Gear Manager and Fitness for Gear. Both same version. I see you have also the Gear Fit Manager twice.
What is your version number for the Gear Manager, and what phone do your have? I have version 2.2.14092499 and Samsung Galaxy S4+