The Dropbox app for Android only lets you access one Dropbox account at a time. But what if you have more? B1 File Manager lets you access multiple Dropbox accounts at a time. You can do so through the “Add Network” option. This will prompt you to sign into a Dropbox account to setup. Once that is done, you can tap it again to add another account. However, this file manager doesn’t offer local sync though. But it makes it easier for you to transfer or delete files in your Dropbox accounts.
Source: Lifehacker