A centralized timer for tracking kids' time on various devices.
The total time spent on various applications / websites is stored in a central server. The server has a web-based administration console that can be used to link kids' profiles, and allocate time per day/hour/week.
This is a work in progress, that I'm building in my free time. The vast majority of where my kids spend their time is on ubuntu and their kindle fire tablets, so I'll be focusing on those sub-projects (as well as the admin) first.