PhoneGap has a plugin-based architecture. Each device-specific feature is a plugin, which consists of javascript and native sides. Js side should be as cross-platform as possible, whereas native side can be implemented only once, for 1 device. Nevertheless built-in plugins are developed for all of the most popular platforms, so no need to reinvent the wheel.

This architecture, together with open source code, not only allows a developer to fix their bugs, but also allows them to tweak their plugins for as per requirements. Also, a developer can build his own plugin, and support any platform of his choice.