If youre flying in Western Europe and some other non-US locations (New Zealand, Australia, S. America) this seems like it could be a leading choice for a moving map navigation app. Loading the free openstreetmap.org maps, or paid aviation charts, for a variety of countries is very easy. Im not going to review the app functions in detail - they all seem to work as advertised, both in the planning stage and in flight. For myself, Im a low time VFR pilot in the US that mainly makes 2-3 hr. trips to build experience (and have expensive lunches,) and I still plot my flights on paper charts with the rigor that my instructor drilled into me. I thought Id try AIr Navigation Pro as a GPS backup and for this it is very good. Transferring my paper routes is easy and monitoring my progress in-flight is reassuring. The Air Nav Pro instruments work well and are a great backup feature that I hope Ill never need. I often fly close to mountainous areas so I particularly appreciate the elevation profile ahead. So my niche is a low cost, lower function alternative to Foreflight or WingX. Here is my only grumble. When I purchased, the top in-app buys were 99c individual sectionals, but now one can only buy charts for the whole US, for $9.99. Because I live in L.A. I also need the TAC, which means second set of TACs, also for the whole country and also for $9.99. And theyre updated twice a year. $40/yr in maps (at time of writing) is peanuts compared to the rest of my hobby so I dont mind, but it puts the cost of AIr Navigation Pro much closer to that of Foreflight. I dont own the latter but once I start venturing further from home it seems to have planning and editing features that more powerful and polished than those in Air Nav, such as fuel pricing on the map and a more logical way to add waypoints. Air Navigation Pro is a good app at a reasonable price that is great for Europe (where the app developer is based) and some other non-US locations. For low time US users its a good entry to GPS moving maps but the pricing structure might make you consider alternatives.