Great question, Thigpen!
In terms of the services that you can have with our usage controls, the actual allowance is the extent of the restrictions you can set. Anything for specific services like e-mail or messaging (yahoo) is not an option with our Usage Controls. You can, however, search the Google Play Store for a 3rd party application that may assist you. We do not support them, but there may be one out there for you!
We do have Content Filtering available on select devices (http://bit.ly/OWlNXn) however, this will be for all services not suitable for 13 and other age levels. It would not give you the option to block specific services.
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