Vocabulary and reading drills are everywhere. A conference paper argues the microphone is the missing input.

Open almost any Japanese learning app and you will find flashcards, stroke order diagrams and reading drills. What you will rarely find is an app that asks you to open your mouth and speak.

Japanese is one of the most popular foreign languages in Indonesian higher education, and also one of the hardest to learn. A wave of mobile learning apps grew up around that demand. The authors observe that the popular ones train the same three skills: vocabulary, writing and reading.
Speaking gets left out. That is an odd omission, because conversation is usually the reason someone starts a language in the first place, and it is the part a classroom has the least time to rehearse. An app that never listens to the learner cannot correct pronunciation or build the reflexes that speaking needs.
The proposal is speaking input treated as a first class interaction. Instead of tapping an answer or dragging a character, the learner says it out loud. The application is meant to deliver listening and speaking practice in a form that feels natural on a phone, using the microphone that every device already carries.

This is not a report on a finished product. Its stated objective is narrower and more useful: to investigate whether the speaking method can support mobile learning at all.

The evaluation concluded that the overall functionality is feasible for future implementation, with a usability score of 81.0. The authors present that as an invitation to keep building rather than as a final verdict.
A feasibility score answers one question and raises several. Pronunciation feedback needs speech recognition good enough to be useful on an ordinary phone. Practice also needs a shape, because repeating a phrase alone grows dull quickly. The interaction has to hold attention for weeks, not minutes, before it can replace the drills learners already accept.
Brata, K. C., & Brata, A. H. (2018). An Idea of Interactive Japanese Language M-Learning Application to Support Listening and Speaking Exercise. 2018 International Conference on Sustainable Information Engineering and Technology.