VueScan, NAPS2, XSane, PDFill, WinScan2PDF, gscan2pdf, ScanDrop, SilverFast, Skanlite, SwingSane, FreeKapture, PaperScan, Scanitto Pro, Scanned Image Extractor, Mopria Scan, CloudScan, Softi Scan to PDF, Smart OCR, AXPDF Scan to PDF Converter, Flegita are some alternatives to Simple Scan.