[dirkf]

Firefox Focus on Android basically does that by default.

If you set it as default browser then all links you click will be openend there. Hit the back button when you're done and everything is deleted.

Another use case is if you quickly want to open some website to look something up: open the website, maybe click a few links, and when you're done everything is wiped.

You can keep a regular Firefox (or Chrome or whatever) for surfing to those websites where you want to keep some state.