Android. It seems to be available on Google play ( https://play.google.com/store/apps/details?id=com.hsv.freeadblockerbrowser) now but I remember having to find the APK elsewhere when I first got it.
Hmmm, that isn’t open source, I don’t know if one can trust it. Why does a browser need in-app purchases? Try Mull or Cromite.
Edit: from the description, it uses Brave Search (to answer you question), so it doesn’t send to Google your queries. But I’d be careful with an app with a bunch of SEO keywords in its description.