Letty

Letty is a file-sharing application that lets you download and upload files. All uploaded files are encrypted and the key to decipher (the "hashcode") is only known to person who uploaded the file.

The passwords are not stored on the servers, which guarantees the anonymity of users stored data. Also, the program can monitor system clipboard for new hashcodes, it can download them automatically, and when it's finished - it will turn off your computer.