Guys, What's the best local deals app for travelers in US?

Not looking for yelp :)

I'm traveling to NY - Florida - Houston - San Francisco and then back to New Zealand, so looking for an app that helps me discover new places and save $$ while i am travelling.

Most importantly, I want the app to have watchlist functionality where i can save things i want to see/go to .. app notifies me if/when it finds them? Thanks!