There are plenty of Android apps which scan documents in greyscale but, even at low resolution, the file size is large (200K or more). And the quality at 75dpi is terrible. Are there any apps which will convert a scan into true B&W, i.e. monochrome, just like a flatbed scanner? I find such images to be sharp and the file size small (often under 50K), which is perfect for archiving hundreds of documents. If there is no app which does this, is there any workaround, e.g. another app which will batch convert lots of greyscales into B&W mono?