Yes! Mavis Camera Classic supports both digital and optical zoom.
Digital zoom is available on all phones and works in 1080p. To access the digital zoom use a tap & drag gesture on the viewfinder.
You can select between either a wide-angle or telephoto lens. To alternate between each lens just double tap the viewfinder.
For more information about zooming (including the zoom gestures) take a look at this dedicated support page: Digital & Optical Zoom