Call Encryption App Costs More Than Your iPhone. If you really had reason to encrypt your phone calls — or were on the payroll of the MI6 – perhaps a $1,600 yearly subscription to a cell phone call encryption app service would make sense.
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While the app is free to download, both the caller and the receiver have to join the service that costs several times more than their phones. [Cult of Mac]
Alternately, you could buy Groundwire for $9.99, and then spend another $24.99 on “ZRTP For Outgoing Calls” as an in-app purchase if you want to make outgoing encrypted calls. Support for incoming calls is included in the basic app, and no yearly subscription is required. The price difference is so enormous that I can’t imagine any legitimate reason why anyone would pay for the overpriced option. I therefore must conclude that it really is intended only for government employees.