Pocket Sensei is a Japanese language learning tool. It teach you more than 8000 most common words, over 2000 kanjis and hiragana and katakana grouped by Japanese Language Proficiency Test (JLPT) levels 1 - 5.
Tool asks different character, reading and meaning combinations and remembers your progress. Works completely offline.
You can add widgets on your homescreen to make the learning easier that ever. The results can be synced between the devices with the cloud.