To add the Android widget, just long press your home screen and then select Microsoft To-Do from the widgets list. Please know that the app will need to be installed directly on your device's memory rather than on an SD card. Apps installed on an SD card are not able to show widgets on Android.
You can quickly add new to-dos to My Day, as well as view your existing to-dos directly from the widget. You can also easily open and access any list. Just press the list's name in the widget and the list will open in Microsoft To-Do.