Scanbot is AWESOME. So is Readle’s Scanner Pro. I think they’re the two best iPhone scan apps, and they basically match or leapfrog each other, year after year. I own them both, and they both work so well I can’t delete one off my phone.
Edit scans, perspective correction, optimize color (I typically scan documents to grayscale), automate uploads to Dropbox, or email them, or fax them, or OCR them, or add saved signature to documents - they do so much more than Apple’s notes scanner.