Windows Store device apps
Windows 8 lets device manufacturers create a Windows Store app that works with device metadata to serve as a companion to their device. These apps are referred to as Windows Store device apps. With device metadata, Windows Store device apps can automatically install the first time a device is plugged in and have more capabilities than regular Windows Store apps. Windows Store device apps are able to leverage the full range of functionality of a device and can perform privileged operations. For more info, see Windows Store device apps.
If you're looking for info about Windows Store mobile broadband apps, see Mobile Broadband.
Accessing devices without device metadata
You don't need to use device metadata to access a device from your Windows Store app. Without device metadata, a Windows Store app can communicate with many types of devices, such as printers, scanners, removable storage, light sensors, motion sensors, and location sensors, to name a few. To learn more, see Integrating devices, printers, and sensors.
In Windows 8.1, Windows Store apps can communicate with USB, Human Interface Devices (HID), Bluetooth GATT, Bluetooth RFCOMM, and Point of Service (POS) devices without any device metadata. For more info, see Communicating with peripheral devices (Windows Store apps).