+x+x+xI would also like user-PDFs to be stored in the cloud and synced :-)
How much would you be open to pay for all the storage space needed?
Yes, other solutions offer that, but at much higher price tag.
Yes, you are right. I had not considered that.
But is there any way I can save my own PDFs stored on the device, e.g. before reinstalling Skydemon or iOS or when changing the device?
Are they included in the iOS backup?
AFAIK it depends on how you do the backup - by connecting to a computer the documents should be there, but when using the iCloud backup I guess not.