OK, I went ahead and bought it tonight. These are my impressions:
** DISCLAIMER: I'm not associated in any way to any of the developers for this or any other application that I mention in this review. **
The flash card system coupled with the pronunciation review COULD have been a killer combination, only if they had implemented it properly
Right off the bat, this is a much better application than MyWords. Why? Because of the inclusion of the (very simple) flash card system. Granted, MyWords will eventually grow to have more than the 2,000 words that come with WordPower, but without a flash card system MyWords it's pretty limited as a learning tool (not to mention that the 10 words that you get daily with MyWords don't seem to have any rhyme or reason for their order of appearance, other than the fact that they show up in related podcast files)
The flash card system is a VERY simple design: If you know the word, the card is removed from the deck, if you don't know it, then it's kept in the deck. This may sound like it's good enough for a flash card system, but it's not, for the simple reason that once you mark a word as "known", it will not be presented again until you are finished with the whole deck!
What's surprising is that they would use such an algorithm for the flash cards, considering that the Leitner system for learning with flash cards is so well known (see wikipedia at http://en.wikipedia.org/wiki/Flashcard )
As it is, if you don't need the pronunciation help, you'd be better helped with some of the other offerings for the iPhone like "Japanese Flip", which comes with 6,000 words and phrases as compared to WordPower's 2,000