This was done in ArtRage. This is an app on my iPad. I haven't used it much before, so I decided to give it a go. A few days ago I went out about an hour and a half before sunset and do a quick sketch. I decided to do a "simple" subject. The light was moving faster than I would have liked, but in 40 minutes or so, I got this. Still not used to the app, but I think I will be using it more...