Wisephone+, which sells for under £10 on the three platforms, is a voice-over-IP overlay that uses existing SIP-based VOIP services such as SIPgate, for example, but encrypts the data stream to secure the IP transmission path.
This is achieved, Infosecurity notes, through the use of SRTP - secure real-time transport protocol - which supports various forms of authentication and encryption between the user device and the VOIP service provider's systems. These authentication protocols usually involve the use of the AES encryption standard.
If two SRTP-capable devices connect via a wholly VOIP connection then the voice call cannot be eavesdropped.
If, however, the VOIP call progresses on to regular landline or cellular networks, then eavesdropping on that leg of the call - i.e. beyond the VOIP server's outdial ports - is possible.
Wisekey says it developed Wisephone understanding that interception technology exists and is used more than many are aware.
Particularly with the increased data stored and transmitted on smartphones, eavesdropping and wiretapping are a genuine concern, the firm says.
People, corporations and governments, the firm adds, need to be aware of the real dangers of voice communication interception and take necessary precautions against hacking, corporate espionage and cyber-terrorism.
Gary Shainberg, Wisekey's chief innovation officer, said that by using the Wisekey app, people can be assured that their conversation will stay away from prying ears, thanks to the high level of cryptography used.
"Wisekey is using its globally recognised, digital security pedigree to make the internet safe for its users", he said.
"This is just the first iteration of the Wisekey secure communications suite, with more applications coming in the near future", he added.