I've been using Maprika for about 6 years and it has been a really helpful tool in finding spots to research. I am now trying out an app called onX for locating land owners after I find those possible sites using MAPRIKA.
I'm not familiar with Maprika, but I do use onX for hunting & metal detecting. I also use Historic Map Works & Historic Aerials with the overlay features to compare maps then & now for finding old sites.