When full disk encryption had a significant impact on performance, I used to store only my most important files encrypted with EncFS in Dropbox. Unfortunately this made it impossible to access the files on the go from foreign computers.
Therefore, I created a standalone browser app which is able to load the encrypted EncFS volumes via the Dropbox API and decrypt them. This happens completely in the browser without any backend, no unencrypted file, key, whatsoever is transferred anywhere or leaves the browser.
Currently, the app cannot be used anymore, as it is using Dropbox API version 1 which is not existing anymore. Nevertheless, it should be fairly straightforward to adapt to their new API or use different cloud storage providers, if anyone wants to use it again.
The source code can be found here: