I have 32GB iPhone and 32GB iPad .. When trying to back up both to iCloud I get told I don't have enough storage space.. If iCloud storage doesn't account for apps what about music, videos and photos? I don't think I can back up my devices with just 5GB?
iCloud back ups that you have the app installed, and app settings.
Try going to Settings- icloud- storage & backup - manage storage - pick your device you're using.
Here, you can tick what data is backed up on an app by app basis.
This list is in size order, which i'd assume your camera roll will be top. I have this unpicked because I find photo stream does this for me.
Next for me is instapaper, which uses lots of data saving images to local memory, however I don't need this because I'm always connected, o i've unpicked that too.
Unticking these options does not prevent the app itself backing up, it just doesn't back up the apps data.
Maybe you have apps installed that I haven't come across, but I think you will find after your camera roll, the size of these back up options will dramatically drop off to under 1mb per app.