I have made my own flash cards for hiragana and katakana but Ive been trying to study kanji, so far Im only through some reviewing for hiragana but its really worth the 8$. Its pre made flash cards with sounds and Im assuming kanji will have explanations with it, so this along side of kanji study is a super awesome learning tool.
Walkin the dog about Learn Japanese!! - Hiragana, v1.1.10