I tried this free app, Docr, to scan a book. https://youtu.be/RRShg2mu6bM It automatically detected a curled page boundary & still manually adjustable. Then, dewarped / converted it to a flat page. Tried its magic shadow removal & color enhance function. Saved as PDF and annotate Email it out, sync / export to iCloud Drive, or upload to Google Drive, Dropbox, Box.net etc. No annoying ads in the app.