For example, a link saving app like Pocket might check if your clipboard currently contains a URL when you open it. That allows the app turn a slightly tedious operation (tap/hold input field to bring up context menu, tap paste, tap button to save) into a single tap ("save copied URL?").
Whether or not the convenience is worth it might be debatable, but I fail to see how one would call that nefarious.
It does appear that lots of apps don’t use these APIs, the developers probably never knew the existed till now, but there is a privacy preserving method of the building the functionality you talk of.
I don’t think that’s the case. You can check if there’s a URL in the clipboard but that’s a UTI thing.
Most of the URLs would likely be in the “strings” section of the clipboard.
Chrome uses it so the URL appears when you select the address bar.
I can totally expect others to detect copied URLs that may belong to the app's domain and then offer to direct you to that particular URL (for example, I think the SomethingAwful app on iOS does that - if it detects a forums.somethingawful address it'll offer to load that particular thread for you).
That said, I definitely want to see more visibility about when and why this is done. Apple are absolutely in the right to show me a popup whenever it happens, so apps are forced to be clear and transparent about it.
It’s disappointing to see the lack of skepticism applied on a site like Hacker News.