Maps are based on Google maps and you can use in the same way you use standard maps: moving around and zooming in/out using your finger gestures or provided zoom controls.
When you open map window you start with rain radar centred at your location at a medium zoom level:
Using the button you can alternate between several layers:
In the bottom bar you have the navigation options:
If you press on current showed time (TODAY 08:30 in the screenshot) you will see a list of all time steps.
You can also move in time with the Previous and Next actions (the arrows) and also animate with Play.
Don't forget to use the more actions or menu button if you don't see all the above actions.