Requirements: Android 5.0+
Unlocked Pro version.

Tap Scanner app is a simple Camera document scanner app with high quality PDF output. Scan documents, receipts, QR and business cards. Use Tap Scanner app to scan any type of document and save the scan to PDF! TapScanner has many filters to help you get the best image quality when you scan a document!

https://play.google.com/store/apps/details?id=pdf.tap.scanner&hl=en