Dropbox for Windows and Windows Phone 8.1 has been updated to carry over some features recently added to the Windows 10 version of the app. While there isn't a changelog specific to the Windows and Windows Phone 8.1 versions, developer Rudy Huyn took to Twitter to note that the update includes new features like quick search, comments and more. From Huyn:
"Dropbox for W8.1 and WP8.1 updated including some new features recently added to the w10 app: comments, quick search, improved UI, etc…"
The update also presumably includes jump lists to access your recently-used files as well. If you're still runnign Windows Phone 8.1 or Windows 8.1, you can check out the latest version of the Dropbox app at the link below.
Source: Rudy Huyn (Twitter)