Microsoft Lens is described as 'Trims, enhances, and straightens scanned documents or whiteboards, exports to PDF, Word, or PowerPoint, supports text extraction, and saves to cloud storage' and is a document scanner in the photos & graphics category. There are more than 50 alternatives to Microsoft Lens for a variety of platforms, including Android, iPhone, Windows, iPad and Android Tablet apps. The best Microsoft Lens alternative is Pocket Scanner. It's not free, so if you're looking for a free alternative, you could try OSS Document Scanner or FairScan. Other great apps like Microsoft Lens are Google Lens, CamScanner, Snagit and GImageReader.
Office Lens is adapted to many platforms, but if I talk about iOS, I choose Pocket Scanner.