It seems to work for voice calls. I can't really see any reason to use this over Redphone unless you need interoperability with iPhone users or need calling outside of the countries that Redphone supports. Kryptos drains battery because it needs to keep a network connection open. Redphone doesn't because it uses SMS for signaling. Kryptos is $10/month. Redphone is free. Redphone also wins on transparency. We know very little about the Kryptos protocol or codec (AES, RSA - that's it.) Redphone is open source and uses ZRTP which is an open standard. We know, for instance, exactly how Redphone mitigates man in the middle attacks. Csipsimple is another alternative for free encrypted calls using the ZRTP standard. It inter operates with other ZRTP clients like acrobits on the iPhone and Jitsi on desktop computers. Put that together with a free SIP (e.g. Callcentric) account, and you can have cross platform encrypted phone calls for free instead of paying $10/mo.
Works Works on galaxy note... 10$ monthly subscription monthly though, make sure you use google checkout or paypal, not their own site, my cc 'suddenly' got used by someone else...
Good app This app works well most of the time but not always. For $10 a month I would expect it to be flawless. I am now using "voip one click" for free encrypted calls and encrypted chat, works well and I have had no problems with it.
Update Font size for input Font size to input data is ridiculously small for a 5.1 in android screen.
Not really free For anything to work after downloading, they demand and subscription and payment.
Get redphone its better Get redphone its better.sorry Mr developer but you charge to much.its a nice application though
Convenient open source app makes free, encrypted calls using open standards.
Linphone is an open source internet SIP phone or Voice Over IP phone (VoIP).