(best viewed in landscape)

Why does the light sometimes take a while to respond?

- Jack of Light uses the camera to turn on and off the flash.  Each focus operation is relatively granular and, depending when you choose to turn the light off, there may be a wait to the next opportunity for the flash to go off.  Results vary per device.

Why doesn't the light on my phone come on?

- Some phones have a high performance flash that cannot stay on for sustained periods (e.g., the HTC Mozart).

Why doesn't the phone go to sleep right when the sleep timer expires?

- The app cannot put the phone to sleep. When the timer expires, it enables the "sleep on idle" option so the phone will sleep within a minute or two if there is no user interaction.