Before someone says “no demo, no sale” (and no, I’m not a fan of the App Store either) I’d like to say that this is actually a very nice app, and something of a bargain compared to most serious OCR apps.
It has a very specific remit: to turn scanned images into searchable PDFs with hidden text. The workflow from scan to output is very quick and simple, and it does not require specialist document scanners.
It does however offer limited control over the scan, with no previews, so while it works fine with predictable originals in standard sizes, I generally prefer to pair it with VueScan or throw prescanned images at it. (They don’t have to be PDFs; most formats seem to work fine.)
The OCR is no more perfect than any other OCR, but it is good, and easily good enough for the intended purpose. Acrobat probably does a marginally more accurate job, but at a much higher price and in a klunkier way. OCR-ed text may be copied and pasted from the main window without saving the file, so it can be used as a quick route to text, but don’t expect clean formatting.
You have to watch file sizes: PDFScanner can downsample images, and provides a useful estimate of file size in the Save DB, but in some cases these can unaccountably balloon. The dev, who is very responsive, is working on this and other things. I don’t think this is going to be one of those apps that is cobbled together for the App Store and then forgotten.