Privacy Protector pro for Android
You can create secret contacts (or make secret your existant contacts) and all the phone activity related to these contacts will be redirected to the app, there will be no trace of them on your logs or sms history, dial ***1111 to launch the app (yes the app doesn't appear on your launcher, the app is totally invisible) and you will find your secret call log, secret sms, files...
You can also hide pictures and videos and store them as secret content accessible only via this application.
default launch number : dial ***1111 to launch the app
Setup your password and launch number (make sure you choose a strong password)
PS: if you forget your password or launch number you will not be able to access the application again(for security reasons)
Enjoy your privacy