Characterized by, done in, or executed with secrecy or concealment, esp. for purposes of subversion or deception.
OK. Sorry it's so late for the word of the day, but I think this works out well.

The phone has an application called "Flashlight" that just lights up the phone. That type of lighting technique has been used all over, including some films - it can be set on the dashboard of the car near the speedometer to shine on the driver.
The idea came from this post on Strobist. The whole situation is just a really cool way of thinking of light in a way that you might not otherwise come across. It's not just that the app is cool, but it's also the fact that you can use ambient light to compose your photo.
Sorry again for the late post - as always, send your clandestine photos to me in an email!