This site lets you practice the kanji and vocabulary typically found in levels N5 through N1 of the Japanese Language Proficiency Test (JLPT).
It’s easy to use. Click the ‘Kanji’ tab and choose which of the five levels you’d like to practice.
Then, click ‘Practice’. As you are presented with each word, type its rōmaji equivalent (e.g., ‘genki’).
Real Kanji App