I am the creator of KeePass DX and I see this post by chance after a little navigation on the net.

Firstly, why not leave a comment on github or on the Play Store or on my email? This is normally the places to request a new feature with at least one link to the article.

I'm a new registered on steemit and I do not really understand how this kind of article can help me develop new features and fix bugs if I have to search in all the web pages.

Secondly, what is the purpose of making screenshots with a line addition "online database storage"? It opens an FTP connection? It connects to a particular cloud? It opens a file manager?

To answer precisely the question of the relevance of this feature :

KeePass DX is a password management application for Android that uses keepass files, and for me, it's not his purpose to synchronize these files on servers but the role of the phone's file manager (which is better for encapsulation and reuse of phone tools).
In addition, I only want to put tools under free licenses (and many cloud storages uses private servers, we don't know what they do with the files.) But nothing prevents to make a separate file manager tool that communicates with Keepass DX to provide the file and metadata necessary for synchronization.

Instead of "online database storage", a synchronization button that allows to check the consistency of the data with a file synchronized by the file manager. The click on the button would merge data in case of conflicts if the synchronization is done both on the application and from the remote server. (With an explanation here)

The synchronization feature will be in development after the release of the stable version of the application, you can see the development progress directly on github.