https://kivy.org/doc/stable/api-kivy.uix.screenmanager.html
https://kivy.org/doc/stable/api-kivy.uix.popup.html
https://kivy.org/doc/stable/api-kivy.uix.dropdown.html
https://stackoverflow.com/questions/44770222/kivy-with-menubar
https://www.geeksforgeeks.org/python-window-size-adjustment-in-kivy/
https://stackoverflow.com/questions/26314466/get-textinput-value-in-kivy-app
https://github.com/techwithtim/Kivy-GUI-Example/blob/master/main.py#L3
https://techwithtim.net/tutorials/kivy-tutorial/example-gui/
https://kivy.org/doc/stable/api-kivy.uix.textinput.html
https://stackoverflow.com/questions/15689555/how-to-create-simple-kivy-app-form-with-field-name
https://github.com/kivy/kivy/wiki
https://kivy.org/doc/stable/api-kivy.html
https://kivy.org/doc/stable/guide/basic.html#quickstart
https://kivy.org/doc/stable/tutorials/firstwidget.html
https://kivy.org/doc/stable/tutorials/pong.html
https://kivy.org/doc/stable/gettingstarted/first_app.html