Here is a brief description of this amazing new feature:Backup Folder
The Android - Blackberry - Kindle version of the Rainbow application has a similar interface with the iOS version, and it offers all the features that the iOS version does. The only features that are missing are those to share a file over bluetooth or to email it.
In particular, you can copy/delete as many files as you like from any cloud service to any other cloud service or from one folder of a cloud service to another folder. You can rename a file, create a folder, and copy or delete a folder.
The Rainbow application copies (or deletes) all the contents of a folder (the same applies to the subfolders). Thus, you need to be extremely cautious when you delete a folder, because you may not be able to recover it again. If something goes wrong you will see an error message.
As with the iOS version, this version has a powerfull search engine that enables one to search for a file / folder using a key-word. The search engine will search in all connected accounts. More importantly, the search engine allows one to transfer many files from different account to the selected folder.