A good question! Your phone app is using some deterministic model or a "hodge-podge" of gridded products to deliver your forecast, all of which are likely low-resolution and a single forecast.

You immediately run into problems with that approach because we live in a state with many climates (which requires high resolution data), models have biases as they're run deeper into a forecast period, and single model forecasts don't show potential uncertainty like what I've been doing here the past few days.

The company I work for is developing a solution to this issue, I'll recommend whichever app takes our data in the future :)