Nestio is a relatively new startup in NYC that helps aggregate listings among other features, but it doesn't seem to be a disruptive startup from the perspective of solving the issues you mentioned.

I went through a broker and a super fast, easy, and great experience, but I was also wary of dodging some of those spammier looking firms you see on Craigslist and other places. Good luck finding no-fee places on Craigslist, don't even try. No-fee seems to be viable only if you scour the city for buildings that display their management info and you swoop in at the right time to claim a place directly. Alternatively, take over someone else's lease.