If you go to "profile" and click on the account you want to save you'll see a button that's called "export". If you click on that button you will get a message that says: "dont share this code with anyone". You gotta click on "confirm". Then you'll get a code. Just copy the code and place it in a document or write it down.
If you accidently removed the account you can go to "profile" again and click on "import". Just put your code there and you'll get your account + all your worldrecords back.
Hope this helps :D