The version labeled 50 of the Opera browser for Android comes with an improved ad blocker that features a site-specific setting, picture-in-picture support for videos on Android Oreo (and later), support for dark CSS themes, as well as support for the Estonian, Latvian, and Lithuanian languages.
https://www.notebookcheck.net/Opera-for-Android-50-comes-with-publisher-friendly-ad-blocking-and-picture-in-picture-mode.410459.0.html