The basic nuts-and-bolts are a bit different from the computer clients. Once you’ve downloaded the app you’ll need to log in to your Dropbox account or set one up if you don’t already have one. However, because of the space limitations, it isn’t ideal (or possible, in many cases) for your device to download the entire folder; instead, the default settings of the apps only let you view your folder. If you’d like to actually download a file you need to mark it as a “favourite” – only then will the app make that file viewable while offline.
Because the Dropbox apps never actually download your folder or its contents (unless a file marked as a favourite) these apps require an active Internet connection. Wireless, 3G or 4G will be suitable for this task, but if you don’t have access to the Internet via any method of connection you will only see your “favourites.”