BlackBerry has been talking about headless application, but we have not seen one, till now. To be honest, I do expect the big major application makers such as S4BB, Dauden or Bellshare to be the first in line, but it seems like Aerize has beaten them to the game. This application, the first ever application to use the headless API is Aerize Lockpic.
Aerize Lockpic allows you to have separate home and lock screen images, and now with headless application API support it can fully run in the background. Previously, BlackBerry 10 applications could only simulate background processing as active frames, which meant that if the application was closed, background processing will stop.