A company believes a glowing pebble could be the easiest way to secure internet-connected devices across a home. Dojo uses a traffic light system to keep users up to date on threats to their smart devices.

The logic behind the product is that as the “Internet of Things” brings ever-more home devices such as thermostats or smoke alarms online, managing security will become more complicated.

Its answer is the Dojo, a router-like box with a removable “pebble” that can be placed anywhere in the home. The box will act as a master firewall and analyse traffic on the local network while the pebble will glow to indicate the current status.

Green means all is fine, orange means there’s a problem which Dojo is automatically addressing, and red means there’s a problem which requires user intervention. The details will then appear as a message in a smartphone app, which can also deliver push notifications. With red alerts, the app will often give a range of possible actions to take, letting the user select and activate with a single tap.

According to the makers, the box never looks at the content of data going into and out of devices. Instead it monitors patterns of activity and looks out for anything unusual such as sudden increases in the amount of data being transmitted from a particular device. The idea is that the box will refine its checking algorithm over time based on user response to alerts.

The downside is that the pricing strongly suggests the product is aimed at those who’d rather splash some cash than spend time and effort tinkering with security settings. It will costs $199 (or $99 for pre-orders) and after the first year there’ll be a monthly service charge of between $7.99 and $9.99 depending on payment schedule.