You can change the colours of features like roads, parks and buildings or turn labels off. It is also possible to draw various shapes and symbols, add text on top of the map, or measure distances and areas. After you’ve finsished you can save your map as a PDF file.
For UK users the app has a whole host of extra overlays based on Ordnance Survey data: administrative boundaries, heritage and scenic sites, nature reserves, geology and height contours. These layers contain related information which you can access by clicking on the features when shown on the map.