Dropbox has updated its Android and iOS apps to make it easier to open shared links within the app. If you get sent a Dropbox link and you open it on your phone or tablet, it will open the said file or folder right within the app instead of through the mobile browser. If the document is already linked to your account, it will just take you to the account to do more with the file like rename it, favorite it for offline access, move it, etc. And if it’s a Microsoft Office file, it can be edited right from Office apps.
Source: Dropbox