If you are a photographer, I can recommend Sun Seeker on iOS. It integrates with compass (so you can see, e.g., where the sun will rise/set in real time), but also has this map mode showing sun position relative to terrain, angle relative to horizon, etc., at a given time of any day. Though it doesn’t try to paint shadows (which I think would be error-prone anyway for most locations), it is a one-time purchase that costs comparatively little and does not try to upsell a premium version.