Some apps re-route requests for opening websites. They don’t cause network traffic themselves, but they redirect users from or to specific non-free websites when following a web-link.
Nitterizeme: re-routes twitter-links to a configurable nitter instance and youtube-links to a configurable invidious instance. While Nitter and Invidious are free-software they’re still basically an alternative front-end for non-free web-sites. So if twitter goes down, or should twitter decides to block nitter instances, nitter would be defunct. So there’s a very strong dependency here. Same goes for the relation between invidious and youtube.
(related Issue I’ve been working on: https://gitlab.com/fdroid/rfp/issues/1211)
NeoLinker (formerly Netscope) redirects web-links to web-sites which perform services like web-search, virus-scans, etc. Some of those web-sites are free others however are non-free (virus total, gibiru). So this app itself does not cause any network-connections but is (suggesting) to redirect web-links to of non-free websites.
(related issue I’ve been working on: https://gitlab.com/fdroid/fdroiddata/-/merge_requests/6351)
Initially I was under the impression I should get those apps tagged with Non-Free Network Services anti-feature, because these apps integrate non-free websites into user experience. However app-authors and some members of our team don’t seem to agree. So naturally I’m interested in, whether our users would expect these apps to be tagged with Non-Free Network Services anti-feature or not, I know I would.