Dropbox adds mobile prompts for two-step authentication, here is how they work
For example, there are times that network coverage is not good enough to allow you to receive text messages so that you can log in to your Dropbox account using two-step verification. This is especially troublesome if you don't keep track of emergency backup codes provided to you by Dropbox, or when you don't have the two-factor authentication code generator with you.
The new two-step authentication method seems like a great new feature to replace the notification via text message option. It also comes in handy since it works even when you don't have cell signal because you can use Wi-Fi connectivity instead.
source: Dropbox
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