iPhone 7 Plus Wall Mount Phone Holder

I'm an engineering student and wanted a way to watch my youtube videos for school while in the shower, instead of just listening to them so I created this. I taught myself CAD since I'm an EE major so if you think you could improve on it feel free to. I also work on airplanes so I grabbed four countersunk screws from work to use with this, however I don't remember the size. This thing works perfectly, and holds my iPhone 7 plus great, with or without my thin case and is designed at an angle so t