The source code for the existing Silent Text version is here and the company tells me that the new Silent Textsource code will be released sometime in March or April after confirming legal issues such as licenses for third-party libraries.
Source code can also be distributed in text-based form like a PDF or scanable book which is what MIT did for Phil Zimmermann and later what 70 international volunteers did for the PGPi Scanning Project in 1997.
He went to Dubai instead, the source said, where he sent a text message saying he had gone to Yemen to start a new life and that it would be difficult for anyone to reach him because he had thrown away his SIM card.
While Russia did alert U.S. authorities about Tsarnaev's possible extremism, it kept out some facts, namely text messages referencing his desire to join a militant group, the source said.