Can I get more info on why these are showing up? I've never seen such a thing on F-Droid before.
Its a nice feature
Many apps need security patches from time to time and web browsers tend to need the most security updates outside of the OS.
As far as security goes please use a up to date browser. I would recommend using the official repo for each of those apps.
F-Droid is an installable catalogue of FOSS (Free and Open Source Software) applications for the Android platform. The client makes it easy to browse, install, and keep track of updates on your device.
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