first of all, you have developed a great and much needed tool. Huge compliment on that. As far as I understood (and tested) part of the encrypted data will have about the same file-size as the original. As far as I understand, that still allows a storage provider (or a attacker) to guess what kind of data you are storing. (as for standard file size of a DVD-image for example).
I am almost sure the idea is not new, but wouldn’t it be possible (as an option) to split files up into blocks (e.g. 50 MB).
Thank you again for the great development, and keep the open source spirit up!