To the best of my knowledge, the bulk of the restrictions are implemented by pointing devices to a custom DNS server (a VPN can accomplish much the same but I don't know if this product implements that). The majority of the app is the user interface for the reporting/status capabilities. You can read a bit more about the implementation on the HN discussion where I discovered this tool: https://news.ycombinator.com/item?id=14913547

> utefan001: After 30 min, DNS no longer works for entertainment sites. [...] It takes her 5 to 7 mins to earn points. My server detects points and re enables DNS replies for YouTube

The somewhat similar Circle product is sold as a device that resides on the local network and accomplishes its configuration using ARP poisoning.