So what can you do is, You can simply activate SHADOW and give phone to your friend. When he/her return your phone again ,you can check that whether he or she did an unnecessary/inappropriate things on your phone. SHADOW will record every key event he or she made during that time including very useful info such as Applications he used,Time they use them, key events and etc.
For the parents, What they can do is they can install this app on kid's phone and activate SHADOW and later on parents can check what are the things done by kids during that period. The things in the sense what are the key events they used. Did they search garbage on internet? or Did he/she texting to someone whole the time he/she supposed to study?
There's a small guide in app itself. Refer below if you face some difficulties.
Guidelines to Users
* Install app
* Activate Shadow (You will directed to the Language and Input Settings in your phone. You need to enable SimpleIME and select it as your default input method)
You are good to go. You can view log file using app. And there are so many features(specially you can authenticate app by providing password which prevents the unauthorized access) .Enjoy Shadowing....!!