When a stranger installs a surveillance app we call it spyware. Does the same apply if it's a spouse?

Domestic spyware monitoring has been quietly booming in the PC world for years without any particularly noticing or caring and now it is looking as if the mobile world will crank the possibilities up a notch or two.

Almost a year ago, a US firm called Gizmoquip released a subscription-based Android app called SMS Tracker that has drawn the attention of US security firm Zscaler thanks to a number of powerful surveillance features the developer aims at parents looking to monitor their children’s tablet or smartphone use.

Because SMS Tracker can do anything the user (i.e. the parent) agrees to during install that means it can do anything at all and on multiple devices at one time. The list of its capabilities is impressive: SMS monitoring, browser tracking, detailed call logging, and of course GPS tracking.

Importantly though, it comes in two versions, one of which shows an icon and privacy screen when it is running in the background and a second hidden version for parents whose children have been diagnosed with “oppositional defiant disorder,”  a completely bogus and Orwellian-sounding condition peddled to American parents who don’t get on with their kids.

It should be pointed out that this app is perfectly legal and doesn’t misrepresent itself in any way so what are the concerns?

“In any other context, an application with these capabilities would clearly be labelled as spyware,” chides ZScaler.

“The vendor is promoting this application as a tool for monitoring the mobile activities of your children. However, this same app would be a very effective tool for spying on someone once installed on their phone.

“You just need to install the app on the device which you want to spy and you are done. All the information about the device and all call and SMS logs can then be remotely monitored.”

In other words there is a potential for this kind of app to be abused by anyone with access to a mobile device. Customers also monitor the data seen by SMS Tracker using a portal which means that what it collects is being stored in an online system.

SMS Tracker is far from alone in the mobile surveillance market and even a cursory search turns up what looks like a mini-boom in this kind of software.

Questions about the limits of legitimate use and the right to privacy remain unanswered but in the US the courts have finally and belatedly woken up to the issue of domestic surveillance in the market where it all quietly began a decade ago, the Windows PC.

In recent days, a former US sheriff was handed a probationary sentence after admitting he installed a keylogger on his wife’s work PC in order to keep tables on her communications. His is by no means the only example of this kind of home snooping gone haywire.

The acid test is whether mobile security programmes notice these apps and let the owner know that their device contains an app granted unusually intrusive permissions. Curiously, Zscaler suggests that fewer currently do if the app was downloaded from Google’s Play store rather than the app vendor's own site.