New idea inspired by a dream:

A #DeathNote, only it's a digital tablet the size of a cell phone.

Pros: built-in camera with a search feature which serves the same function as #shinigami vision

Cons: battery life sucks and you have to spend a couple hours recharging after every use

Twist : Company that makes them run by shareholders who are all secretly shinigami who collect all the years taken by the devices no matter who the user is. (It's in the terms of service but who reads those?)