Google has announced that now you can see third party apps in your Google Now cards. However this only works on Android with about 30 third party apps. So now, instead of getting customary Google Now notifications on traffic, weather, flights, packages and so on- you can now directly get data in your Google Now cards from third party sources outside of Google.
Here is an example:-
If you want to see more example cards, you can visit here.
Google has partnered with few selected app developers for this and has not explained how to get your app included here yet. It is unclear when and if Google will expand it to more developers.
The list of partners include leading companies like Airbnb, Instacart, Pandora, Shazam, Lyft, TripAdvisor, KAYAK, eBay, Walgreens, Ford, Waze, Strava, Duolingo, Mint, The Economist, The Guardian, Belly, Coinbase, Redfin, Zillow, Life360, Hootsuite, Wattpad, Runtastic, Delivery Hero, Hailo, mytaxi, busuu, ESPN, Housing, ICICI, Meru Cabs, Shaadi, The Economic Times, Cookpad, SmartNews, Suumo, BookMyShow and Lincoln.Now Get Data In Your Google Now Cards From Third Party Sources!,