<p>I can’t block anything that my kids would not be able to unblock 
I try not to worry about it as longs as grades/commitments are OK.
My S has an android, so occasionally, if I know he really does have a lot to do, I will ask him to leave the phone in the kitchen. This way he can still use it if needed but is not being distracted by constant texting…see, texting is a culprit here ;)</p>