It was an idea from the Angry GM. The idea is that, as time passes in the game world, the GM adds dice into a bowl. If I remember the idea right, when there a six dice, the GM rolls them, and any show up a 1, you get a complication, like a wandering monster.
Basically, if players are more likely to run into monsters or whatever the more time they spend mucking about, you want a visceral way for them to understand how much time they're spending on different tasks. It's a tool to create tension and drive them to action when there is a time pressure.
I'm not sure it's the right tool for encouraging exploration, since it's whole purpose is to get the players moving, and spend less time poking at things.