Hello, Dar Slijepcevic
Welcome to the Microsoft community.
Thank you for your feedback.NAPS2 is a free, open source PDF scanning software that supports Windows, Linux and macOS systems. From several sources, NAPS2 is recommended as an effective scanning tool that simplifies the document scanning process and provides an intuitive and easy-to-use interface.
Regarding the User Account Control (UAC) warning you receive, this is usually a security feature of the Windows operating system used to alert the user that an application wants to make changes to the system. This warning is normal when installing a new application, especially if the application requires changes to system settings or files. Since NAPS2 is open source software, its publisher information may appear as "Unknown" because open source software is usually developed by the community rather than commercial companies. This does not necessarily mean that the software is insecure, but it does require users to pay more attention when installing it.
Whether or not NAPS2 is the best alternative to Windows scanning applications depends on your specific needs; NAPS2 is prized for its cross-platform support and ease of use, but if you need specific features or advanced settings, you may want to consider other options. When choosing an alternative, it's important to consider your specific needs, such as scanning quality, feature richness, user interface and compatibility.
Finally, if you have concerns about the security or suitability of NAPS2, Microsoft is not responsible for this as it is third-party software. You can do some research such as checking user reviews, forum discussions or professional software reviews to get more information about the software.
Please let me know if you have any other questions or if I haven't explained something clearly.
Best Regards,
Aaron| Microsoft Community Support Specialist