The Windows version of the remote app is in your Presonus account. Make sure you are looking at Windows versions of the program though otherwise it won't show up. i.e. if you are looking at the MAC OS systems versions.
It's under My Products/Software/Studio One 3 Professional/View More Details/Installers
Make sure you select Other Systems here if you are looking at Mac installers.
I have Studio One installed on an iMac as well as my studio Win7 machine. I run the remote app on an iPad as well and it finds either install perfectly. It is a very handy app actually.