What is Reddit's opinion of LRトレーナー 英語 L R 発音・聞き分け・スペル練習?

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I made LRトレーナー for practising English L/R sounds (it's in Japanese). The audio's terrible and there's no reason to use it beyond an hour or two, but I thought the UI was half decent for a first app, and it was a good learning experience.