"FOSS Browser" is fully free/libre (as in freedom) Android app. The source code is public on Github. The app also does not need any unnecessary permissions.

A simple Android browser based on webview. The base is "Ninja" (https://github.com/mthli/Ninja). The intention is to provide a simple and light wight but powerful browser with a nice looking user interface.

The app is complete adfree, open source and needs no unnecessary permissions:
https://github.com/scoute-dich/browser

Links:
- Download: https://github.com/scoute-dich/browser/releases
- Watch Changelog: https://github.com/scoute-dich/browser/blob/master/CHANGELOG.md
- See license: https://github.com/scoute-dich/browser/blob/master/LICENSE.md)
- See screenshots: https://github.com/scoute-dich/browser/blob/master/SCREENSHOTS.md)
- XDA - Link: http://forum.xda-developers.com/android/apps-games/app-browser-t3500091)


Security/Data:

- no unnecessary permissions
- enable/disable cookies, javascript, location access, history
- save login data in separate, encrypted database
- whitelist for javascript, cookies and AdBlocker
- toggle image loading
- backup data
- AdBlocker


UI/Handling:

- optimized for one hand handling (toolbar at bottom)
- tab control (switch, open, close unlimited tabs)
- Android 7 app shortcuts
- full material design
- fullscreen browsing (optional)
- navigation button in fullscreen mode
- request desktop site


Some nice extra features:

- full oreo support
- search on site
- open links in background
- Websearch (from marked text context menu)
- screenshots of the whole website
- build in file browser (open, share, delete files)
- open links in other apps (for example YouTube)