Independent product · Energy
OctoSpy
A personal energy chart turned into a free public dashboard that reached 10,000 visitors in its first week.
Visit projectProblem
Smart-tariff households could see what they used, but not why a bill changed or whether another tariff would have cost less.Solution
A read-only dashboard that works from the customer's own half-hour readings, straight from Octopus into the browser.Impact
10,000 unique visitors and strongly positive feedback in the first seven days, with 70+ improvements shipped on day one.
The problem
Octopus Energy customers on smart tariffs such as Intelligent Octopus Go, Agile and Tracker pay different prices through the day. Supplier apps show usage, but rarely answer the questions people ask: how much did the car cost to charge, why was this week dearer than last, and would a different tariff have been cheaper?
The solution
OctoSpy began as my own chart for splitting house and EV electricity costs after switching tariff. It became a public dashboard for daily spending, usage patterns, export earnings and published rates, with a fictional demo household so anyone can explore it before connecting an account.
Comparisons built from recorded half-hour readings
Compare Tariffs replays each recorded half hour against the historical prices of every supported tariff, including standing charges and VAT. Usage Patterns splits a change in spending into energy used, blended rate and standing charges, so a higher bill comes with a reason.
The evidence
OctoSpy fully supports 17 import, export and gas tariffs, and a public support page states what each one covers. The calculation rules sit apart from the interface and are covered by 287 automated tests, including incomplete price data, which is never treated as zero.
Private by design, read-only by choice
The application is static. The browser talks directly to Octopus, and OctoSpy’s servers never proxy or store readings. Stored readings are encrypted in the browser, with an optional passphrase-protected vault for remembered connections. The product only reads and explains; it never changes tariffs, devices or charging schedules.
The impact
OctoSpy went from a working name to a public launch on Reddit within a week. It reached 10,000 unique visitors in its first seven days, and the response from Octopus customers was strongly positive.
Bug reports and requests from those first users became more than 70 shipped changes within a day. A dashboard built for one household found an audience of thousands.
The result