How often do I have to buy this

It worked fine and then one day it told me I had to buy it again?

Frankly, I am very angry about it. Now I have a whole bunch of photos that I cant get to (cant even see) without repurchasing the app.

I bought this once. Unless you plan on re-buying this app whenever the maker feels like they want to extort more money from you, then dont buy it in the first place.

808AA about Camera 3D Pro, v1.9.1