Just installed it and I love it. Just have to figure out how to save and access the documents on my IPad now. I did email one to a friend, which worked effortlessly. Do I have to save them to iCloud or Dropbox?
Scanner Pro will keep a copy of your saved document. You can leave them there if you like. It is even possible to place them in folders. Similar to placing apps in folders, just tap and hold on a document then drag it onto another document or folder. To change the document or folder name tap the Edit button, then tap and hold the document or folder.
You can use some of the popular cloud services: DropBox, Google Drive, and WebDAV are supported. These are only upload options, as far as I can tell, but you can access the same cloud services from a number of iPad apps and, of course, other devices and computers.
iCloud is useful if you have more than one iOS device and want them to stay synced. However you won't be able to access the synced documents outside of Scanner Pro.
If you want your documents organized, available just about anywhere, and the scanned text to be searchable, the Evernote support is great. You'll need a paid account or the searchable text, but if you're heavily into note keeping I think it is well worth it.
Another options is to use the Open In sharing options. With this you can send copies of your documents (as JPG or PDF) to another app. Apps like GoodReader and PDF Expert not only have the ability to store your PDF scans in an organizable file structure, but will allowing you to annotate the files as well, marking or drawing on them as you please. There are several other PDF apps that might server you better, depending on your ultimate needs, but those are the two I'm most familiar with.
And you can export to other compatible apps as a JPG, to the Photos app camera roll if nowhere else. That could come in hand now and then.
Many other options, and you're not stuck using one or two of these features. Enable and use as many as you like. That's what I do. After all, what use is a scanner if you can only do one or two things with the results.
Have fun.