DapSync Light allows you to synchronise your iTunes library with non-Apple devices. It is a simple single-click application which uses the iTunes library directly to keep track of tracks on your DAP.
DapSync Light keep track of what is already downloaded, but can also check that tracks are really on your device and re synch if needed. DapSync also provides support for splitting your library across two devices, which is needed for DAPs such as the Fiio X5.
DapSync Light is fully functional but is limited to the first 1000 tracks in your library. A full version is also available for a small fee. DapSync light is available for Windows and Mac.