Work on a weather routing algorithm for sailing and let it use the ACCESS model and you'll blow PredictWind out of the water...

Considering how difficuly rain forcasting is for weather models, only HRRR really nails it with constant radar data assimilation every 15 mins, I think you have done an admirable job with the nowcasting. Its a very useful feature. As others have mentioned - a "heavy rain starting near you in X minutes" feature could be cool similar to the 'Rain Parrot' app. Keep pushing Windy team. Your the best out there, love what you do. You make weather look so good