This app was mentioned in 7 comments, with an average of 6.14 upvotes
I've tried quite a few travel organisation apps, and the one I keep coming back to is Tripit. You can set it up to import itineraries directly from Gmail, or you can forward emails manually, both of which work really well, even with non-English emails. The UI isn't the prettiest, but it's well organised and easy to quickly find the information you need like a booking reference or seat number. It also has a web version for desktop, which is pretty useful for when you do have to input information manually. It even syncs with other services like PackPoint.
Don't bother paying for the Pro version though.
I recently used Tripit: https://play.google.com/store/apps/details?id=com.tripit
TripIt
https://play.google.com/store/apps/details?id=com.tripit
Haven't used it in a while but worked for me in the past...
I love TripIt