The trips feature in Inbox is incredibly useful, but I hated having to go back to the email app and scrolling till I find the trip details. So I'm glad they came up with a new app to manage your trips.
https://support.google.com/inbox/answer/6228360?hl=en under the "Find your Trip in Inbox" header
I'm generally happy about Inbox/Google Now features, but this one was a small annoyance in my trip this month.
There are others. Unfortunately (for the airlines I use at least) there's no way for Google Now to know that a re-booked flight is not a new flight. I routinely need to change flight dates/times several times, but still get Google Now notifications for the original flights.
I've had mild panic attacks on several occasions when I saw the "you need to have left for the airport two hours ago to get to your flight on time" popup.