Those of you interested in preserving your privacy will want to watch out for the mSpy app. When installed on an Android or iOS device, it can track phone calls, location data and keyboard strokes in the background without your knowledge.

The app is ostensibly intended for legal monitoring use, and there are certainly legitimate reasons to install the software. Companies, for instance, could inform their employees that they’re surveilling company phones for security purposes, or concerned parents could include the software on devices they give to their kids.

mSpy dances around the legal issue of surveillance with the following disclaimer on its website:

My Spy (mSpy) is designed for monitoring your children, employees or others on a smartphone or mobile device that you own or have proper consent to monitor. You are required to notify users of the device that they are being monitored.

However, elsewhere on the company’s website, the mSpy refers to the app as a bugging tool for gathering evidence, ominously referring to the user of a tapped phone as the “target.” mSpy also claims that its software is “100% undetectable,” which shouldn’t be necessary if everyone has been informed that they’re being monitored.

Screen Shot 2013 11 27 at 3.46.59 PM 730x416 mSpy: A terrifying app for spying on another smartphone or tablet user

A sales rep said the following when I asked:

After complete installation the application runs in a stealth mode, so it is undetectable and completely invisible for the target phone’s user

Thankfully, the app requires physical access for installation. The iOS version requires that the client device is jailbroken, and it isn’t currently compatible with iOS 7 and recent versions of iOS 6 (6.1.3 and 6.1.4).

mSpy for Android works with some of the platform’s most popular devices, including the Galaxy S4, Moto X and the HTC One, but spying on apps like Facebook, Skype, Viber and Whatsapp requires the phone to be rooted. Older BlackBerry and Symbian phones are also supported.

Screen Shot 2013 11 27 at 3.47.15 PM 730x303 mSpy: A terrifying app for spying on another smartphone or tablet user

We’ve had to come to grips with the fact that the government has been spying on our phones, but now we also have to deal with the possibility that our loved ones and employers could be tracking us as well. Disconcertingly, mSpy claims to have over 1 million paid users.

If you’re interested in using the software for a  reason, plans start at $40 a month. I, for one, will be keeping my phone close at hand.

Image credit: CoolKengzz / Shutterstock