This is Coppernic Android repository for common software.

Currently it serves 61 apps. To add it to your F-Droid client, scan the QR code (click it to enlarge) or use this URL:

http://fdroid.coppernic.fr/common/fdroid/repo

If you would like to manually verify the fingerprint (SHA-256) of the repository signing key, here it is:
73 24 15 96 B5 B3 9B E1 52 3A 3F F5 94 8A 84 64 2E 08 3E 4F 12 28 D0 C3 86 9E 37 CA B9 C5 E7 74