The library interface is now sufficiently general that adding support for a new storage service basically involves implementing auth, file selection, file download, and file upload.
There are at least two challenges in adding support for Dropbox:
The Dropbox API has no concept of file IDs. The current library interface assumes that every file has a unique ID. This might be simulated by using the file's path, but this would break things when a file is renamed.
Using the Dropbox API requires approval from Dropbox. I don't know how much work this requires, and what happens when a new version of the app is released.
The library interface is now sufficiently general that adding support for a new storage service basically involves implementing auth, file selection, file download, and file upload.
There are at least two challenges in adding support for Dropbox: