Funnily enough, I just went to download the app, checked the in-app purchases and saw the list you've posted here, then promptly closed the App Store.

How much does this app cost? Who knows?! Does a "Week-to-Week Flighty Pro" subscription cost $4.99 or $7.99? Why is Week-to-Week Flighty Pro $4.99 in the list twice? Same for Annual Savings Flighty Pro $59.99. Apple have made such a fucking mess of in-app purchases that we end up with this kind of rubbish, and I can't place any trust in a developer who allows their in-app purchases list to look like this. So they just lost a sale.