Google Trips allows you to sync your Gmail account, which will populate the app with all of your upcoming and past adventures — all flight, hotel and car rental information is available in one place for each trip. Before heading out on your journey, download the city you’re going to so you can access all of its features offline.
This seems promising. Definitely going to try this on one of my upcoming trips, letting it sync up as I get my confirmation emails. If you beat me to it, come back and let me know how it worked out for you.