'Full Nav Capability' is somewhat limited on Memory Map, because the map is just an image. It knowing nothing of the airspace boundaries, or aiports etc, and relies on you to warn yourself, or plan yourself.
PocketFMS on the other hand can offer a solution for not much more that provides far more functionality than either unit (more functionality in fact than most systems out there).
For the £55 unit mentioned in the article, add a €150 subscription (appx £120) gives a total price of £170.
For this you have a fully fledged GPS system with full airspace warnings, full flight planning, weather systems (including rainfall radar), and world wide coverage.
This includes both the mobile version, and the full pc flight planning system.
For the sake of clarity, I should point out that I'm a Beta Tester for PocketFMS. I've no financial involvement...just a happy user that enjoys testing the software before it's released to the public
dp