During last week F3F world championship, I tried an App, which also exists as a web site (https://www.windytv.com), and which is a great tool for our hobby.
We usually use Windfinder or equivalent weather forecast App giving the wind speed and direction, with sometimes the exact direction in degree, or rain forecast, temperature, etc ...
But what is missing is the mapping of the wind direction forecast applied on a map or satellite photo.
And this is exactly what Windyty proposes. This free App/Web include weather forecasts provided by meteoblue (meteogram, airgram, etc ...), but the best part is really the animation of the wind on a satellite photo, where you can see the evolution during the day, or the next days. Graphics are really nice, and nothing is missing as you can select the altitude, rain accumulation, temperature. The App is also very intuitive.
I greatly recommend this App if you have a smartphone, so you can see if the wind direction is correctly oriented to you local slope, or select the right slope among several slope.
The example below with one of my favourite slope "La Muela" in Spain, where you can see in purple the lines indicating the wind direction. The speed of the animation indicates the wind speed. the bar at the bottom allows to see the evolution of the wind speed/direction over a period of time.