This app has great customer reviews and it is excellent for learning basic Japanese Kanji.

• includes cards for the first 440 Japanese kanji
• learn an English meaning for each kanji
• onyomi and kunyomi readings for each kanji
• over 1500 keywords which use only these kanji
• more than 2000 cards all together
• users may choose which of the thousands of individual cards make up each deck

• get a card right and it's taken out, get it wrong and it's shuffled back in
• add more cards as you work through the whole pack
• swipe gestures for faster drilling
• go back if you need to recheck a card

All the decks are included free, the 1st Year decks cover 80 kanji and over 200 keyword cards. The 2nd and 3rd Year decks cover the next 320 kanji taught in Japanese schools.

Regular practice and review is the only way to build your kanji knowledge.