What is the best spy app?

[Android Central Question]

A friend has a very stubborn, tech savvy, and increasinly naughty young teen. She heard about apps that can "spy" on her daughters phone without her daughter finding out. The dad pays/runs the phone accpunt but they both have eaual custody of the daughter. She doesn't want to push her daughter further away but also wants to monitor her texts to see if there is anything dangetous and illegal happening. Does that technology really exist?

 

[chanchan05]

It does, but not sure how "secret" it would be from a tech savvy teen. Practically most parental permission apps have certain features to track the kid's location and sometimes internet activities. Although it would have to be consent from both sides as the teen finding out that the mom is trying to "spy" on her would lead to further rifts between them. If she's tech savvy I'm sure she will find out.