Why would you want an iOS app for linkedin? Unless you are a recruiter it's just not a daily use kind of thing.
I don't really understand why most people use apps for things that are essentially websites that don't have unusual latency requirements. I mean, sure, maps and some of the other daily use things, those extra microseconds matter. I want to do more of it locally. But things like linkedin and facebook? the ios browser works fine for that (well, I haven't figured out how to make facebook messages work through the mobile website... but there's no way I'm installing that app)