Adobe Scan - Scan anything to PDF

[Ink]

The free Adobe Scan app turns your device into a powerful portable scanner that recognizes text automatically (OCR). Turn anything — receipts, notes, documents, pictures, business cards, whiteboards — into an Adobe PDF with content you can reuse.

• CAPTURE. Scan anything with precision. Advanced image technology automatically detects borders and sharpens scanned content.
  
• ENHANCE. Touch up scans or photos from your camera roll. Easily preview, reorder, crop, rotate, and adjust color.
• REUSE. Turn your scan into a high-quality Adobe PDF that unlocks content through automated text recognition.

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It is basically capable of capturing your documents, enhancing them, removing the noise, and providing them in an editable PDF or even Microsoft Office Word format. Adobe claims here that the underlying tech is more advanced than it looks.
Source: Adobe launches Adobe Scan app with reusable content and Adobe Document Cloud integration