Mendeley - Easily organize your papers, read & annotate your PDFs, collaborate in private or open groups, and securely access your research from everywhere.

Scanbot - Scanbot is a mobile app that allows you to use your device's camera as a document scanner. The app is capable of scanning a large number of source materials, and it can handle QR codes as well.

Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.

Office Lens - Download this app from Microsoft Store for Windows 10, Windows 10 Mobile, Windows Phone 8. 1, Windows Phone 8, Windows 10 Team (Surface Hub), HoloLens. See screenshots, read the latest customer reviews, and compare ratings for Office Lens.

Qiqqa - Qiqqa is a free research and reference management software. It can be used in many organizational projects from the academic to the personal to the business endeavor. Read more about Qiqqa.

Scanner Pro - Scanner Pro turns your iPhone into portable scanner in your pocket.