When I try to activate the GPS facility I receive the following message; 'Location Services Denied'.
This is standard IOS behaviour, if you refuse location services twice within the app you never get asked again.
To reset it go to Settings->Privacy->Location Services->The_App_Name and set it to "While using App" or "Always"
How do I add new markers or points of interest to the maps? is there a help guide.
Within the app in the 'Map information' ~ 'General Information' you should find a section on how to use Map Markers.
Why do I need to pay again for the latest A-Z map?
Much the same as purchasing a paperback A-Z atlas, the latest versions with new A-Z mapping are not available free of charge and will not automatically get installed.
Geographers' A-Z Map Company Limited create, publish & continually update over 300 maps, atlases and digital maps covering many locations within Great Britain.
This is an expensive process and as such the licensing arrangements we have with A-Z does not allowed us to offer free updates to any of the A-Z mapping.
Updates to the app that just involve feature upgrades or bug fixes (using the same A-Z mapping data) will however be free of charge and should automatically install.