Meanwhile, I improved Fossdroid with these features:
* A better material design layout
* Screenshots of apps
* HTTPS (thanks to Let's Encrypt and Cloudflare)
* Trending apps
* Open source (https://github.com/SnaKKo/Fossdroid-Core)
I need to thanks also the F-Droid team for the great job to spread the open source apps on the Android platform.
https://fossdroid.com