This is a third app I recommend for anyone to use. I was introduced to this app many years ago, maybe around 2012. This app has been out for a while, but I picked up to use the app a bit more this semester when submitting work. CamScanner, scans paper documents from your phone and can be converted into a pdf. And you have options to remove the shadows and lighten the image. The cool part about this app is that you can adjust the corners of what youre scanning (taking a photo of) to the corners of the document you just took a photo of, so on your phone, the photo will come up in a flat dimension, making the document straight on your phone instead of any weird tilts and warps to the image compared to taking a normal photo of a document on your phone.

My example was a quick photo, just to reveal the settings.

But with much more precision, you can get a much clearer and nicer image of your scanned document. I use this for when I need to upload stencils and sketches onto the computer. And take out photos of important documents.