This is a "must have" for those of us concerned about cloud security. I've tried a number of encryption programs (including ones web based like BoxCryptor) and they all have various issues. This application does (at least for me) one thing, and one thing very well. It allows me to encrypt my files prior to sending them to cloud storage. I do a simple backup to the cloud and I'm secure knowing that no one can get access to that data. And the folder structure stays intact (not an archive format), the file names remain the same, and the encryption and synchronization process is fast.
I recently had one issue with certain files (about 5 out of a total of 5500+) in my documents folder not being backed up and the developer worked with me over the Thanksgiving weekend to resolve the issue. Even sent me a "test" version prior to loading it up on Apple's App Store. Great support! If you're concerned about file security, you need to try Crypt Sync Files!