"State of Surveillance", Episode 4.13 of the HBO series VICE features an incredible demonstration of cell phone spy app capabilities.
The featured app is so powerful that Edward Snowden feels the need to demonstrate how to physically disable cell phone's mic and camera(see image above) so that journalists will be safe from tracking and spying.
The cell phone monitoring app in the show is FlexiSPY and the feature the episode focuses on is call recording.
See the video below, where a security researcher demonstrates how easy it is to record journalist's sensitive phone conversations with FlexiSPY. Click on the image to open the video in a new window.
It is easy to see that FlexiSPY's phone recording ability is very powerful for a commercial app. As seen in the screenshot below, all phone conversations are recorded by FlexiSPY and stored on a server, where the operator can easily access them at their convenience.