This is an example of a sign in screen that validates a username and a password. Feel free to import this fully editable project into your own account for use in your prototypes.
Use the following to successfully sign in and proceed to the next screen
User Name: john
Password: proto.io
I replicate this cool "Switching tabs" animation by talented Jokūbas- https://dribbble.com/shots/1984025-Switching-Tabs
For the creation of this animation, I simply used various state transitions.