TripIt is a travel website with an app I use frequently. I’m sure it does more, but I use it to store travel itineraries in 1 place. The key factor for me is instead of manually entering all my travel information all I need to do is forward the confirmation email to TripIt and they automatically pull out the relevant information and create the trip. I usually get flight information first so that’s what my trips are created with, but when I later send confirmations for hotels or rental cars it automatically adds that information to the existing trip.
There is also an option to give it access to your email account so you don’t even have to take the step of forwarding the emails, but I don’t use that because I’m not a big fan of giving out access to my email account.
I use the free version, but there’s also a Pro version that adds flight delay and gate change notifications. I believe it also notifies you if the price of your flight has dropped so you can request a refund from the airline.