An extensible framework for offloading data traffic sent to a mobile computing device over a cellular network to a wireless network comprises software plugins, a plugin host that is typically part of the mobile device operating system, and plugin interfaces through which the plugin host communicates with the plugins. A plugin is associated with one or more mobile operators. The framework can comprise one or more plugins, but typically, only one plugin is active at a time. The framework can automatically detect and connect to wireless networks associated with a mobile operator associated with an active plugin. The plugin can automatically authenticate the mobile device or a mobile device user with the mobile operator over the connected wireless network. The plugins are not allowed access to operating system functions responsible for detecting and connecting and disconnecting to a wireless network, which can improve mobile operating system stability and battery life.