Tools & Utilities
WattLens
See what each device costs you — in money, not kWh.
Turn smart-plug watts into tariff-accurate device costs.
Why WattLens exists
Smart-plug and energy-monitor apps show live watts and kWh, but never what a device actually costs under a real tariff with tiers, day/night rates, or a standing charge. WattLens translates local power readings into tariff-accurate euros per device, all on your own device or LAN.
What WattLens does
- Device registry with name, room, source, and nominal/standby watts
- Tariff editor: currency, standing charge, single rate or day/night windows, and tiered thresholds
- Manual reading entry (watts now, or kWh over a period)
- Optional LAN read from Shelly, Tasmota, ESPHome, or Home Assistant endpoints you configure — off by default
- Cost per device per day, month, and year, plus a portfolio total
- "Replace appliance" payback estimate and ranked energy offenders
- CSV/JSON export
- Fully offline — no account, no subscription
Screenshots
Privacy and local storage
WattLens stores all device and tariff data locally. Energy-usage patterns can reveal when you are home, so it is built privacy-first: the network is used only for LAN meter endpoints you configure yourself, it is off by default, and credentials are stored encrypted on your device.
Full privacy policy for WattLensAffiliate links disclosure
WattLens may include a single, non-intrusive "Recommended hardware" entry with clearly-labelled links to energy-monitoring and TOU-aware smart plugs.
Get WattLens
Get it on Google Play
Google Play
Play Store listing coming soon. The app is under active development.