Not that I am lookinging forward to use a non-integrated , non unified messaging solution but since the days of true mobile device progress 2009 - 2010 we have learned to lower our expectations Jitsi for Android is now in Alpha development stage and at least this program is built with encryption in mind. XMPP and SIP seem to be supported on Android. Quickly tried it on a Galaxy Note 3 , ZRTP seemed to work but the other end (OSX) did not receive voice from the mobile device. Jitsi is growing to be by far the best multi-protocol IM client with strong encryption.