Dropbox is a web-based file hosting service operated by Dropbox, Inc. that uses cloud storage to enable users to store and share files and folders with others across the Internet using file synchronization. In order to store data on Dropbox, you must register to obtain a Dropbox account. A variety of different accounts are available, including free accounts that let you upload up to two GBs of data, and paid accounts with expanded limits. For details, refer to Dropbox website.
Open the file inside the Dropbox.
Tap the icon.
Open the file inside the iDocuNote.
Tap the icon.