Weather app to show actual performance of weather models
Ghost Line feature overlays past forecasts on reality to show model bias.

Dark Sky clone with custom rain models, but Carrot Weather already owns this.
iOS users missing Dark Sky's hyperlocal rain forecasts
Carrot Weather · Dark Sky · MyRadar
Here's how GrayCloud works: * Raincast: minute-by-minute rain prediction and accumulation tracking for your exact location * Forecasts: 10 day forecasts use multiple high resolution sources and correct for bias at your location. * Alerts: rain starting, stopping, severe weather, daily summary and more * Widgets: home and lock screen widgets * Multi-platform: apple watch and mac apps
I use NOAA and ECMWF models for core weather data and a custom model to compute rain accumulation and the next 60 minute radar movements.
I also offer Apple WeatherKit as an alternative weather source.
Ghost Line feature overlays past forecasts on reality to show model bias.
Multi-model ensemble + ML bias correction beats single-API weather apps.
The Drying Core™ is a neat, physics-forward idea — it uses vapor pressure deficit, wind desiccation, solar irradiance and dew-point prediction to produce a single drying score and actionable windows. I like the fabric-specific timing, on-device processing and low-latency rain alerts/widgets; the missing piece is hard validation data and regional coverage limits (WeatherKit dependence), which will determine if this is indispensable or just clever.
Replaces scraping dozens of inconsistent government APIs with one normalized REST endpoint.
Cross-exchange prediction market data without scrolling six platforms; arbitrage finder included.
Stadium sun-shade overlay in real-time; solves a genuine friction point elegantly.