iFlash is an amazing application! I actually do more studying now than I did before. The developer is very responsive, also. While I love this application and definitely think it's worth the money, I have a few suggestions for the developer:
1- give users the option to download\upload attachments from the library. I'm not sure if this is supported or not, but I downloaded a deck of Country flags around the world, and there were no images on them... so I assume not.
2- It might just be me, but when I try to record something into my flash card, all I hear is static. My microphone works fine, too.
3- Support quizzing! Because iFlash doesn't support quizzing, I have to use it along the side of Genius.
4- I think the coolest feature of this program is the ability to share knowledge. The first thing I did was download other decks... even decks that covered what I was already efficient in had information I didn't know. And I also downloaded some decks I don't need, just because I thought it would be interesting, for instance, to learn some Japanese words. The problem with this feature, however, is that the library is still fairly limited. A broader list of categories with more decks in them would be really nice. Here are some ways I would suggest the developer can accomplish this:
A) Offer discounts to trial users who upload X number of cards. This would give users incentive to share their own work, rather than keeping to themselves.
B) Offer discounts for, say, a few weeks where the application will be half off.
C) Get free exposure through a website like www.macheist.com by sharing the application to a bunch of mac users for free.
D) Get free exposure through a site like www.macappaday.com
Increasing your userbase, regardless of how much they paid to get the licensed version (or even if they have the licensed version) will lead to a larger library, thus a better application. And, of course, the more people that love the application, the more people they tell. I've already told several friends to go get it ;)