Ive been studying Japanese for years now and I have to say that Japanese Flip is one of the better ways to accomplish this. Its fun and takes all the strain out of having to compile all your flashcards. Definitely worth the price of lunch at a fast food joint. To put it in perspective I just bought "Kanji Flip" because I like this one so much!
Only a couple of comments / suggestions:
1. some of the entries seem weird (i.e. 隠しカメラ: hidden (spy) camera) and neither my Japanese wife nor I can really believe theyre on the JLPT... perhaps they were added for fun?
2. The author should add the ability to do the flash-card testing by viewing the cards from the English meaning and Hiragana reading as well as from the full word. As it stands now you see the full word and then have to click "Show Answer" to see the English meaning(s) and the pronunciation. Being able to view different "sides" of the flashcards first would allow the student to test himself from English to Japanese as well as Hiragana to Kanji / English. This can help a lot in being able to remember words from the English meaning or from the Japanese pronunciation side instead of just the Kanji side. Add that and I would give it 5 stars.
Magneticplastic about Japanese Flip