There are many devices that sync motion to 18+ content and they are rising in popularity. DeoVr, HereSphere and WhirlyGig implement a timecode server to allow such devices to sync scripted motion to such videos. This is all that is required to make your application compatible with many devices on the market, such as the Handy, Fleshlight Launch, Kiiroo Keon, Vorze and LoveSense.
Other applications take care of communicating with these devices as long as the filenames and accurate timestamps are made available by Skybox, preferably by means of the method linked below as it has effectively become the standard for these things.
The timecode server-format is described on the DeoVr website.