Mobile Phones mobile/smart phone internet security

[Darklordsbane]

Hi All
could you please advise what the best internet security to use on mobile phones is, my kids and missus don't have any afaik
my phone isn't smart and I don't use it on net
number 1 old nokia
Number 2 has iphone 4.5s
number 3 has a htc desire c
and she who must be obeyed has a nokia lumia 610
as always any help greatly appreciated
Regards
D