Actually, I think the WingX Subscription is $0.99 due to some Apple store idiosyncrasy:
Why does VFR Free cost 99c?
Our intent was to make VFR Free! really free. However, there is no Tier 0 (free) pricing option for subscriptions. The next lowest price is 99c. We'll send all our proceeds for VFR Free! subscriptions to a charity that helps children.
You download the app, and select the level of subscription you want. CFI's also get a free subscription. I don't know how that process works.
