You cannot start a list with the new APP without first downloading the Nebraska pack. I did that out there in less than 30 seconds. Started to bird. It works with your downloaded list and the calendar. At any time it will show a list of "likely" birds for that date. If you turn the RARITIES on I believe it will give the entire state list rarities and all. But if you type the name of the bird, it will still pull out the bird from the list. I added Nebraska and a suggested list of neighboring states. Other than that, if you want the 50 states on the phone, you will have to add them one by one. Same with countries.
What most people end up doing is adding the states as you travel. You can do it at your motel or rest stop before venturing out to the weak signal areas. I added a few West coast states and Finland and my list of packet is now this. Note that country lists may be very small and have less data about the seasonal changes. Our US state packets may be as big as 5MB.
There is also a HELP tab, that takes you to your phone browser and will give help on various topics: