The iPhone app came years after the free and open source desktop one; the boat had long since sailed on charging on the desktop. The Android one is unofficial.
I recall reading that because they didn't make the app friendly to casual newcomers, they didn't pick too low a price-point that would attract them and their support load.
That said, complaining about an app's price on HN is pretty disappointing. Though they might have found more success with a recurring/IAP approach that makes payments more palatable.
Seems development has largely stalled on the iPhone app though.
> Maybe they feel like all Apple users are stupid & rich and will pay whatever they are asked for.
That's one way to couch it; another is charge what the market will bear. IOS devs routinely tout all the polls/studies that show Apple customers pay more and more often for software than Android customers.
There's another problem: there's no way to easily make cards from the mobile app! You have to do it on the desktop and then switch to mobile. Really kills the incentive for the mobile app
Apple charges a ridiculous amount in order to be allowed to develop software for their platforms. It is no surprise that developers might feel the need to pass this cost on to the customer.
The author didn't just make it out of the good will of his heart, he wanted to turn a profit and set out to make money off the iPhone version from the outset. The $100 fee is a triviality in the face of the hundreds and hundreds (thousand, even) of hours it takes to create and maintain Anki on iOS. You don't have to look far to see the development of the native version of the iOS app was even contracted out, for pay. It was taken very seriously.
Not all FOSS software developers are against making money. Often FOSS projects can be a starting point to launching a commercial product or service, whether it was originally intended to be one or if a long-time hobby project happened to grow to the point that making a business around it becomes a viable new option.