Dropbox is a great tool, but the official app only allows you to sign into one account at a time. If you need to work with multiple accounts, ES File Explorer, our favourite file explorer for Android, makes things easy.
ES File Explorer allows you to add two or more cloud storage accounts for easy navigation, including two accounts from the same service. Grab a copy of the app from Google Play, fire it up and tap the Fast Access icon to the upper left of the screen.
Tap the Cloud icon, hit New, and then select Dropbox from the list of supported cloud services. At the authentication page, enter the email address and password associated with one of your Dropbox accounts. Repeat the process to add a second, a third and even a fourth account.
You can treat your Dropbox accounts just like local storage, as you can easily copy and move files between locations.
How To Add Multiple Dropbox Accounts To Android [Guiding Tech]