Saima is described as 'AI-based browser extension that increases video comprehension, memorization and focus by introducing personalized adaptive speed. It optimizes the watch speed, removes long pauses, and silences, and trains the brain to keep focus and consume more in even less time' and is an app in the audio & music category. There are nine alternatives to Saima for a variety of platforms, including Google Chrome, Windows, Mozilla Firefox, Mac and Web-based apps. The best Saima alternative is Jump Cutter, which is both free and Open Source. Other great apps like Saima are Video Speed Controller, Video Speed App, Faster Video and HTML5 Video Speed Control.
As to the silence skipping feature, Jump Cutter is fully local. It does not pass any data to any third-party servers, and so it does not require you to accept any privacy policies or EULAs.
Not to mention that it's open-source and free (both as in beer and as in freedom)