If you already used KaniWani for something else, how about KameSame - a fast, feature-rich Japanese memorization webapp? In addition to recalling reading, it is also a Japanese IME practice.
If not using autocomplete from IME, you’ll probably have to use KaniWani. (Or kitsun.io or anything using WanaKana.js, but it has to be Romaji input.)
Otherwise, another option I can think of is some kind of voice transcription. Not sure of from English, but from Japanese, there is LipSurf.