Is it possible to manage cloud storage from a Windows PC?

Hi,

I have an iPhone 5S, and an ipad Air2. Both are running iOS8

I am getting messages on both units that my "cloud storage is getting full". Also that I won't be able to update apps on the phone as storage is getting full.

I have logged into icloud on my PC, but can't open any folders to delete stuff.

I back up my photos from my phone to 2 hard drive locations 1 on my PC, and 1 on a separate networked Hard Drive. (Looking at some sort of cloud storage, but would need 200Gb, so not really considering apple cloud).

How can I free up space on the 5Gb cloud storage (don't really want to pay for more on this option)

What can I do to free up storage on my iPhone and ipad as well. Both are 16Gb units, and both have about 2 to 3 Gb Free space.

Thanks