Open source encryption on mobile phones?

[bobthebuilder]

Hi.. I´m relatively green in this area, but would (for ideological reasons:) like to hear someone comment on products like Cryptophone. They claim to have based their product on open source encryption, but are they really secure, or is it not the same as a closed system that is non transparent for the user, where one only can rely on the word of the producer of the product... A little like religion,,, those to believe or not.

Not many people chose to look into this growing problem "the right to privacy",, so anyone have a comment for the above mentioned product?