Actually, looking at what has been pulled out from Amazon onto his Kindle junior clocks about the same on his mobile phone as on his tablet and proper Kindle combined. So mobile phone I can sort-a accept it - for example he was doing his GCSE Macbeth revision on it in the car yesterday.
Ditto for wikipedia as a starting point (but not a definitive reference).
Now games console... Gootube... Forget it.