Most scanners stop when the PDF is saved. ScanChat PDF lets you scan a page on iPhone and ask the document a question. The answer comes from the file itself and includes the page it came from. OCR makes photos of bills, contracts, and notes searchable. You can also sign, highlight, merge, split, compress, and turn images into a PDF. Scanning, signing, merging, and the search index stay on the phone. No account required. Free on the App Store.