This provides for controlling mobile device functions and features. For example, it limits or disables the use of some of mobile device features which could cause distraction to the user, when the user is engaged in another activity. In an example, it enables other mobile device features based on occurrence of events related to the user or environment. Another example addresses controlling the mobile device features, such as SMS, while the user is in a vehicle or driving. Another example restricts the ability of the driver of a vehicle to text, while the vehicle is in motion, by automatically disabling the texting ability of mobile device within and around the perimeter of the driver's seat. Other variations, examples, improvements, detection mechanisms, models, techniques, calculations, verification mechanisms, and features are also described in details.