nitefall 1.82 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. This free Mac application is an intellectual property of FoxfortMobile.
From the developer:
Nitefall is a Safari extension that converts all your websites to dark mode and reduces eye strain. The application is especially helpful at night. It works automatically with your system's appearance, so that your websites are only dark when the whole system is in dark mode.