I'm using the bing wallpaper app by quiet some now and i feel that it is very insubstantial.
I feel that when you are offering a dedicated app for wallpaper it should contain some basic options to opt for. The only thing it offers is new wallpaper every day that's it. I run my windows 10 pc on dark theme and often times the wallpapers are extremely bright it would be better if microsoft added theme compatible wallpaper features and offer multiple wallpapers per day so that users can have the option of opting for slideshow as I love that feature very much and I'm using slideshow features since years.
It's was good effort to a dedicated wallpaper app but It has very high scope and need for improvement.
