It is much more difficult to provide the same solid level of accountability for mobile devices than for a computer. (We strongly recommend that these devices should be used with much discretion and only out of necessity.)
In the US, the following providers offer content filtering. It is advisable to add this free feature to your phone plan as a first layer of defense.
In Israel, filtering is available from:
Note: This will not help if the phone can access WiFi.
If you are aware of any solutions for mobile devices, not presented in this section, please let us know.