This is an encrypted pastebin, such that the server has zero knowledge of the content. It's intended for small amounts of text less than 32K in length. It's not intended for transfering large files, or for storing pastes for more than a day.
Because this is completely open to any user on the internet you should be wary of the potential for DDoS, and only install this app if you really need to avoid using other pastebins or if other pastebin sites are censored or untrustable. There are traffic limits set within this app to attempt to minimize the potential for flooding attacks, but that might still not be sufficient in the worst cases.
Select *Add/Remove Apps* then *privatebin*. You'll need to enter your preferred subdomain - something like /paste.yourdomain.com/ and optionally a freedns code.