As far as I know, there is only the help section in the app itself that tells you how to set up the database sharing. Other than that I never felt like I needed anything explained.
Do you have any specific problem with the app ?

That is only possible manually by going into each profile and then changing the collection number under "Move/Personalize". Obviously this is extremely time consuming and the better solution would be to reassign the collection numbers by title in the Windows version and then syncing the database.

If you don't need to permanently reassign collection numbers, but want to change the sort order you can do that by tapping on the middle icon at the top of your collection (four horizontal bars and an arrow on the right).