Complex sentence: Decibel functions as a desktop agnostic daemon which uses the Telepathy protocol for communication protocols, adding features to reduce the effort and complexity needed to integrate real time communication into applications.
Split into simpler sentences: Decibel functions as a desktop agnostic daemon that uses the Telepathy protocol for communication protocols. But Decibel adds features on top of Telepathy to reduce effort and complexity needed in integrating real time communication into applications.