downloading app again, how to make sure my accounts are all there?

So I have to remove the app from my phone( to make room for an ios update)... is there a way I can make it so when I download the app again on my phone all my accounts are there (instagram has something like this and so does google photos). Also are the only things I need to do is save my drafts(besides account details) so I loose nothing? Like would save the login be good to do?