Modern smart phones have sophisticated hardware and operating systems and with many senses and features. Some of these features are hardware base such as motions sensors, GPS or camera, and some of software features provided by the operating system such as social sharing, calendar, contact and etc. You can take advantage of them to bring smart features and extra life to apps. All operating systems provide some API to give the access to these features, but they are all very different and sometimes quite complex.
Zebble provides a rapper around all the native devices APIs to bring you a unified API which works consistency on all devices and operating systems. So you do not have to waste time to repeating yourself for every platform.
There are tens of features on the device APIs and we want to go through all of them in detail. But do not wary. As to need to use each particular API, you can use the Visual Studio intelliSence to figure out the details.