Problem:
If you add too many logins, the add button goes off screen. See the screenshot

There are nine logins there, and adding a tenth one is impossible because the button isn't visible.
Possible Solutions:
Use the Kivy screen manager to create multiple screens. From here, put in buttons to move to the previous and next screens. This might require restructuring the code, so this is not a small issue. Another option is to add popups for new pages. This solution is lazy and inconvenient for the user, but it will be much easier. It is unlikely that anyone would want to add more than nine logins, so this isn't a critical issue, although it should be fixed.
Problem:
If you add too many logins, the add button goes off screen. See the screenshot

There are nine logins there, and adding a tenth one is impossible because the button isn't visible.
Possible Solutions:
Use the Kivy screen manager to create multiple screens. From here, put in buttons to move to the previous and next screens. This might require restructuring the code, so this is not a small issue. Another option is to add popups for new pages. This solution is lazy and inconvenient for the user, but it will be much easier. It is unlikely that anyone would want to add more than nine logins, so this isn't a critical issue, although it should be fixed.