Looking for an app that will hold all my reward card numbers.
I.E HHiltons or Delta reward numbers.
Sounds like you're a frequent traveler. I'm very happy with TripIt, and as one of VERY few paid apps, I upgraded to TripIt pro, which does what you want. There are mileage trackers which I've tried and abandoned, but this one is sufficient, and TripIt does much much more (e.g., gate check-in reminders, change reminders, seating advice, easy links to phone numbers, arrivals, options for others to know where you are, etc.)